Communication apparatus and a method for communication

ABSTRACT

[Solution] Provided is an apparatus including: a selection unit configured to select a frequency band to which non-orthogonal multiple access is applied and at least one layer among a plurality of layers that are to be multiplexed in the frequency band for the non-orthogonal multiple access, as a band and a layer to be used for transmission to a terminal device; and a notification unit configured to notify the terminal device of the frequency band and the at least one layer.

TECHNICAL FIELD

The present invention relates to an apparatus.

BACKGROUND ART

Non-orthogonal multiple access (NOMA) has been attracting attention as aradio access technology (RAT) for a fifth generation (5G) mobilecommunication system following Long Term Evolution (LTE)/LTE-Advanced(LTE-A). In orthogonal frequency-division multiple access (OFDMA) andsingle-carrier frequency-division multiple access (SC-FDMA), which areadopted in LTE, radio resources (e.g., resource blocks) are allocated tousers without overlap. These schemes are called orthogonal multipleaccess. In contrast, in non-orthogonal multiple access, radio resourcesare allocated to users with overlap. In non-orthogonal multiple access,signals of users interfere with each other, but a signal for each useris taken out by a high-accuracy decoding process at the reception side.Non-orthogonal multiple access, in theory, achieves higher cellcommunication capability than orthogonal multiple access.

One of radio access technologies classified into non-orthogonal multipleaccess is superposition coding (SPC) multiplexing/multiple access. SPCis a scheme in which signals to which different levels of power areallocated are multiplexed on at least partly overlapping radio resourcesin frequency and time. At the reception side, interference cancellationand/or iterative detection is performed for reception/decoding ofsignals multiplexed on the same radio resource.

For example, PTLs 1 and 2 disclose, as SPC or a technology equivalent toSPC, techniques for setting an amplitude (or power) that allowsappropriate demodulation/decoding. Moreover, for example, PTL 3discloses a technique for enhancing successive interference cancellation(SIC) for reception of multiplexed signals.

CITATION LIST Patent Literature

Patent Literature 1: JP 2003-78419A

Patent Literature 2: JP 2003-229835A

Patent Literature 3: JP 2013-247513A

DISCLOSURE OF INVENTION Technical Problem

When a plurality of layers are multiplexed in the same radio resourcesfor non-orthogonal multiple access, it is necessary for a terminaldevice to ascertain a layer on which a signal destined for the terminaldevice is to be transmitted. However, deciding a layer on which a signaldestined for the terminal device is to be transmitted each time a signalis transmitted may cause a burden of processing of a base station toincrease. In addition, notifying the terminal device of the layer onwhich the signal destined for the terminal device is to be transmittedmay cause a burden to increase in terms of waste of radio resources aswell. In other words, a burden of scheduling of non-orthogonal multipleaccess may increase.

Therefore, it is desirable to provide a mechanism for further reducing aburden of scheduling in non-orthogonal multiple access.

Solution to Problem

According to the present disclosure, there is provided an apparatusincluding: a selection unit configured to select a frequency band towhich non-orthogonal multiple access is applied and at least one layeramong a plurality of layers that are to be multiplexed in the frequencyband for the non-orthogonal multiple access, as a band and a layer to beused for transmission to a terminal device; and a notification unitconfigured to notify the terminal device of the frequency band and theat least one layer.

In addition, according to the present disclosure, there is provided amethod that is performed by a processor, the method including: selectinga frequency band to which non-orthogonal multiple access is applied andat least one layer among a plurality of layers that are to bemultiplexed in the frequency band for the non-orthogonal multipleaccess, as a band and a layer to be used for transmission to a terminaldevice; and notifying the terminal device of the frequency band and theat least one layer.

In addition, according to the present disclosure, there is provided anapparatus including: an acquisition unit configured to acquire bandinformation indicating a frequency band that is a frequency band towhich non-orthogonal multiple access is applied and selected as a bandto be used for transmission to a terminal device, and layer informationindicating at least one layer which is at least one layer among aplurality of layers that are to be multiplexed in the frequency band forthe non-orthogonal multiple access and selected as a layer to be usedfor transmission to the terminal device; and a reception processing unitconfigured to decode a signal to be transmitted on the at least onelayer in the frequency band.

Advantageous Effects of Invention

According to the present disclosure described above, it is possible tofurther reduce a burden of scheduling in non-orthogonal multiple access.Note that the effects described above are not necessarily limitative.With or in the place of the above effects, there may be achieved any oneof the effects described in this specification or other effects that maybe grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a first explanatory diagram for explaining an example of aprocess in a transmission device that supports SPC.

FIG. 2 is a second explanatory diagram for explaining an example of aprocess in a transmission device that supports SPC.

FIG. 3 is an explanatory diagram for explaining an example of a processin a reception device that performs interference cancellation.

FIG. 4 is an explanatory diagram illustrating an example of a schematicconfiguration of a system according to an embodiment of the presentdisclosure.

FIG. 5 is an illustrative diagram for describing examples of frequencybands to be used by a base station.

FIG. 6 is an illustrative diagram for describing an example ofnon-orthogonal multiple access.

FIG. 7 is a block diagram illustrating an example of a configuration ofa base station according to the embodiment.

FIG. 8 is a block diagram illustrating an example of a configuration ofa terminal device according to the embodiment.

FIG. 9 is an illustrative diagram for describing a first example of asignal transmitted on each layer by a base station.

FIG. 10 is an illustrative diagram for describing a second example of asignal transmitted on each layer by a base station.

FIG. 11 is an illustrative diagram for describing a third example of asignal transmitted on each layer by a base station.

FIG. 12 is an illustrative diagram for describing a fourth example of asignal transmitted on each layer by a base station.

FIG. 13 is an illustrative diagram for describing a fifth example of asignal transmitted on each layer by a base station.

FIG. 14 is an illustrative diagram for describing a sixth example of asignal transmitted on each layer by a base station.

FIG. 15 is an illustrative diagram for describing examples of bandwidthsof respective layers.

FIG. 16 is a sequence diagram illustrating an example of a schematicflow of an overall process according to the embodiment.

FIG. 17 is a sequence diagram illustrating an example of a schematicflow of a process of a terminal device according to the embodiment.

FIG. 18 is an illustrative diagram for describing a general frameconfiguration.

FIG. 19 is an illustrative diagram for describing an example of a frameconfiguration according to a modified example.

FIG. 20 is an illustrative diagram for describing a first example of asignal transmitted on layers by a base station according to the modifiedexample.

FIG. 21 is an illustrative diagram for describing a second example of asignal transmitted on layers by a base station according to the modifiedexample.

FIG. 22 is an illustrative diagram for describing a third example of asignal transmitted on layers by a base station according to the modifiedexample.

FIG. 23 is an illustrative diagram for describing a fourth example of asignal transmitted on layers by a base station according to the modifiedexample.

FIG. 24 is an illustrative diagram for describing a fifth example of asignal transmitted on layers by a base station according to the modifiedexample.

FIG. 25 is an illustrative diagram for describing an example of analteration of a length of a time frame.

FIG. 26 is an illustrative diagram for describing an example of a frameconfiguration according to another embodiment.

FIG. 27 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 28 is a block diagram illustrating a second example of theschematic configuration of the eNB.

FIG. 29 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 30 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Note that description will be provided in the following order.

1. SPC

2. Schematic configuration of system

3. Configuration of each device

3.1. Configuration of base station

3.2. Configuration of terminal device

4. Technical features

5. Process flow

6. Modified example

7. Another embodiment

7.1. Technical problem

7.2. Technical features

8. Application

8.1. Application example with regard to base station

8.2. Application example with regard to terminal device

9. Conclusion

1. SPC

Firstly described with reference to FIGS. 1 to 3 are processes andsignals of SPC.

(a) Process in Transmission Device

FIGS. 1 and 2 are explanatory diagrams for explaining an example of aprocess in a transmission device that supports SPC. According to FIG. 1,for example, bit streams (e.g., transport blocks) of a user A, a user B,and a user C are processed. For each of these bit streams, someprocesses (e.g., cyclic redundancy check (CRC) encoding, forward errorcorrection (FEC) encoding, rate matching, and scrambling/interleaving,as illustrated in FIG. 2) are performed and then modulation isperformed. Further, layer mapping, power allocation, precoding, SPCmultiplexing, resource element mapping, inverse discrete Fouriertransform (IDFT)/inverse fast Fourier transform (IFFT), cyclic prefix(CP) insertion, digital-to-analog and radio frequency (RF) conversion,and the like are performed.

In particular, in power allocation, power is allocated to signals of theuser A, the user B, and the user C, and in SPC multiplexing, the signalsof the user A, the user B, and the user C are multiplexed.

(b) Process in Reception Device

FIG. 3 is an explanatory diagram for explaining an example of a processin a reception device that performs interference cancellation. Accordingto FIG. 4, for example, RF and analog-to-digital conversion, CP removal,discrete Fourier transform (DFT)/fast Fourier transform (FFT), jointinterference cancellation, equalization, decoding, and the like areperformed. This provides bit streams (e.g., transport blocks) of theuser A, the user B, and the user C.

(2) Transmission Signals and Reception Signals

(a) Downlink

Next, downlink transmission signals and reception signals when SPC isadopted will be described. Assumed here is a multi-cell system ofheterogeneous network (HetNet), small cell enhancement (SCE), or thelike.

An index of a cell to be in connection with a target user u is denotedby i, and the number of transmission antennas of a base stationcorresponding to the cell is denoted by N_(TX,i). Each of thetransmission antennas may also be called a transmission antenna port. Atransmission signal from the cell i to the user u can be expressed in avector form as below.

$\begin{matrix}{s_{i,u} = {\begin{bmatrix}s_{i,u,0} \\\vdots \\s_{i,u,{N_{{TX},i} - 1}}\end{bmatrix} = {W_{i,u}P_{i,u}x_{i,u}}}} & \left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack \\{W_{i,u} = \begin{bmatrix}w_{i,u,0,0} & \ldots & w_{i,u,0,{N_{{SS},u} - 1}} \\\vdots & \ddots & \vdots \\w_{i,u,{N_{{TX},i} - 1},0} & \ldots & w_{{i,u,{N_{{TX},i} - 1},{N_{{SS},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 2} \right\rbrack \\{P_{i,u} = \begin{bmatrix}P_{i,u,0,0} & \ldots & P_{i,u,0,{N_{{SS},u} - 1}} \\\vdots & \ddots & \vdots \\P_{i,u,{N_{{SS},u} - 1},0} & \ldots & P_{{i,u,{N_{{SS},u} - 1},{N_{{SS},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 3} \right\rbrack \\{x_{i,u} = \begin{bmatrix}x_{i,u,0} \\\vdots \\x_{i,u,{N_{{SS},u} - 1}}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 4} \right\rbrack\end{matrix}$

In the above expressions, N_(SS,u) denotes the number of spatialtransmission streams for the user u. Basically, N_(SS,u) is a positiveinteger equal to or less than N_(TX,i). A vector x_(i,u) is a spatialstream signal to the user u. Elements of this vector basicallycorrespond to digital modulation symbols of phase shift keying (PSK),quadrature amplitude modulation (QAM), or the like. A matrix W_(i,u) isa precoding matrix for the user u. An element in this matrix isbasically a complex number, but may be a real number.

A matrix P_(i,u) is a power allocation coefficient matrix for the user uin the cell i. In this matrix, each element is preferably a positivereal number. Note that this matrix may be a diagonal matrix (i.e., amatrix whose components excluding diagonal components are zero) asbelow.

$\begin{matrix}{P_{i,u} = \begin{bmatrix}P_{i,u,0,0} & 0 & \ldots & 0 \\0 & P_{i,u,1,1} & \ddots & \vdots \\\vdots & \ddots & \ddots & 0 \\0 & \ldots & \ldots & P_{{i,u,{N_{{SS},u} - 1},{N_{{SS},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 5} \right\rbrack\end{matrix}$

If adaptive power allocation for a spatial stream is not performed, ascalar value P_(i,u) may be used instead of the matrix P_(i,u).

As well as the user u, another user v is present in the cell i, and asignal s_(i,v) of the other user v is also transmitted on the same radioresource. These signals are multiplexed using SPC. A signal s_(i) fromthe cell i after multiplexing is expressed as below.

$\begin{matrix}{s_{i} = {\sum\limits_{u^{\prime} \in U_{i}}^{\;}s_{i,u^{\prime}}}} & \left\lbrack {{Math}.\mspace{14mu} 6} \right\rbrack\end{matrix}$

In the above expression, U_(i) denotes a set of users for whichmultiplexing is performed in the cell i. Also in a cell j (a cell thatserves as an interference source for the user u) other than a servingcell of the user u, a transmission signal s_(j) is generated similarly.Such a signal is received as interference at the user side. A receptionsignal r_(u) of the user u can be expressed as below.

$\begin{matrix}{r_{u} = {\begin{bmatrix}r_{u,0} \\\vdots \\r_{u,{N_{{RX},u} - 1}}\end{bmatrix} = {{\sum\limits_{i^{\prime}}^{\;}{H_{u,i^{\prime}}s_{i^{\prime}}}} + n_{u}}}} & \left\lbrack {{Math}.\mspace{14mu} 7} \right\rbrack \\{H_{u,i} = \begin{bmatrix}h_{u,i,0,0} & \ldots & h_{u,i,0,{N_{{TX},i} - 1}} \\\vdots & \ddots & \vdots \\h_{u,i,{N_{{RX},u} - 1},0} & \ldots & h_{{u,i,{N_{{RX},u} - 1},{N_{{TX},i} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 8} \right\rbrack \\{n_{u} = \begin{bmatrix}n_{u,0} \\\vdots \\n_{u,{N_{{RX},u} - 1}}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 9} \right\rbrack\end{matrix}$

In the above expressions, a matrix H_(u,i) is a channel response matrixfor the cell i and the user u. Each element of the matrix H_(u,i) isbasically a complex number. A vector n_(u) is noise included in thereception signal r_(u) of the user u. For example, the noise includesthermal noise and interference from another system. The average power ofthe noise is expressed as below.σ_(n,u) ²  [Math. 10]

The reception signal r_(u) can also be expressed by a desired signal andanother signal as below.

$\begin{matrix}{r_{u} = {{H_{u,i}s_{i,u}} + {H_{u,i}{\sum\limits_{{v \in U_{i}},{v \neq u}}^{\;}s_{i,v}}} + {\sum\limits_{j \neq i}^{\;}{H_{u,j}{\sum\limits_{v \in U_{j}}^{\;}s_{j,v}}}} + n_{u}}} & \left\lbrack {{Math}.\mspace{14mu} 11} \right\rbrack\end{matrix}$

In the above expression, the first term of the right side denotes adesired signal of the user u, the second term, interference in theserving cell i of the user u (called intra-cell interference, multi-userinterference, multi-access interference, or the like), and the thirdterm, interference from a cell other than the cell i (called inter-cellinterference).

When orthogonal multiple access (e.g., OFDMA or SC-FDMA) or the like isadopted, the reception signal can be expressed as below.

$\begin{matrix}{r_{u} = {{H_{u,i}s_{i,u}} + {\sum\limits_{j \neq i}^{\;}{H_{u,j}s_{j,v}}} + n_{u}}} & \left\lbrack {{Math}.\mspace{14mu} 12} \right\rbrack\end{matrix}$

In orthogonal multiple access, no intra-cell interference occurs, andmoreover, in the other cell j, a signal of the other user v is notmultiplexed on the same radio resource.

(b) Uplink

Next, uplink transmission signals and reception signals when SPC isadopted will be described. Assumed here is a multi-cell system ofHetNet, SCE, or the like. Note that the signs used for downlink will befurther used as signs denoting signals and the like.

A transmission signal that the user u transmits in the cell i can beexpressed in a vector form as below.

$\begin{matrix}{s_{i,u} = {\begin{bmatrix}s_{i,u,0} \\\vdots \\s_{i,u,{N_{{TX},u} - 1}}\end{bmatrix} = {W_{i,u}P_{i,u}x_{i,u}}}} & \left\lbrack {{Math}.\mspace{14mu} 13} \right\rbrack \\{W_{i,u} = \begin{bmatrix}w_{i,u,0,0} & \ldots & w_{i,u,0,{N_{{SS},u} - 1}} \\\vdots & \ddots & \vdots \\w_{i,u,{N_{{TX},u} - 1},0} & \ldots & w_{{i,u,{N_{{TX},u} - 1},{N_{{SS},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 14} \right\rbrack \\{P_{i,u} = \begin{bmatrix}P_{i,u,0,0} & \ldots & P_{i,u,0,{N_{{SS},u} - 1}} \\\vdots & \ddots & \vdots \\P_{i,u,{N_{{SS},u} - 1},0} & \ldots & P_{{i,u,{N_{{SS},u} - 1},{N_{{SS},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 15} \right\rbrack \\{x_{i,u} = \begin{bmatrix}x_{i,u,0} \\\vdots \\x_{i,u,{N_{{SS},u} - 1}}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 16} \right\rbrack\end{matrix}$

In the above expressions, the number of transmission antennas is thenumber of transmission antennas of the user, N_(TX,u). As in downlink, amatrix P_(i,u), which is a power allocation coefficient matrix for theuser u in the cell i, may be a diagonal matrix.

In uplink, there is no case where a signal of a user and a signal ofanother user are multiplexed in the user; thus, a reception signal of abase station of the cell i can be expressed as below.

$\begin{matrix}{r_{i} = {\begin{bmatrix}r_{i,0} \\\vdots \\r_{i,{N_{{RX},i} - 1}}\end{bmatrix} = {{\sum\limits_{i^{\prime}}^{\;}{\sum\limits_{u^{\prime} \in U_{i}^{\prime}}^{\;}{H_{i^{\prime},u^{\prime}}s_{i^{\prime},u^{\prime}}}}} + n_{i}}}} & \left\lbrack {{Math}.\mspace{14mu} 17} \right\rbrack \\{H_{i,u} = \begin{bmatrix}h_{i,u,0,0} & \ldots & h_{i,u,0,{N_{{TX},u} - 1}} \\\vdots & \ddots & \vdots \\h_{i,u,{N_{{RX},i} - 1},0} & \ldots & h_{{i,u,{N_{{RX},i} - 1},{N_{{TX},u} - 1}}\;}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 18} \right\rbrack \\{n_{i} = \begin{bmatrix}n_{i,0} \\\vdots \\n_{i,{N_{{RX},i} - 1}}\end{bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 19} \right\rbrack\end{matrix}$

It should be noted that in uplink, unlike in downlink, a base stationneeds to obtain all signals from a plurality of users in a cell bydecoding. Note also that a channel response matrix differs depending ona user.

When a focus is put on a signal transmitted by the user u, among uplinksignals in the cell i, a reception signal can be expressed as below.

$\begin{matrix}{r_{i,u} = {\begin{bmatrix}r_{i,u,0} \\\vdots \\r_{i,u,{N_{{RX},i} - 1}}\end{bmatrix} = {{H_{i,u}s_{i,u}} + {\sum\limits_{{v \in U_{i}},{v \neq u}}^{\;}{H_{i,v}s_{i,v}}} + {\sum\limits_{j \neq i}^{\;}{\sum\limits_{v \in U_{j}}^{\;}{H_{i,v}s_{j,v}}}} + n_{i}}}} & \left\lbrack {{Math}.\mspace{14mu} 20} \right\rbrack\end{matrix}$

In the above expression, the first term of the right side denotes adesired signal of the user u, the second term, interference in theserving cell i of the user u (called intra-cell interference, multi-userinterference, multi-access interference, or the like), and the thirdterm, interference from a cell other than the cell i (called inter-cellinterference).

When orthogonal multiple access (e.g., OFDMA or SC-FDMA) or the like isadopted, the reception signal can be expressed as below.

$\begin{matrix}{r_{i,u} = {{H_{i,u}s_{i,u}} + {\sum\limits_{j \neq i}^{\;}{H_{i,v}s_{j,v}}} + n_{i}}} & \left\lbrack {{Math}.\mspace{14mu} 21} \right\rbrack\end{matrix}$

In orthogonal multiple access, no intra-cell interference occurs, andmoreover, in the other cell j, a signal of the other user v is notmultiplexed on the same radio resource.

2. Schematic Configuration of System

Next, a schematic configuration of a system 1 according to an embodimentof the present disclosure will be described with reference to FIGS. 4 to6. FIG. 4 is an illustrative diagram illustrating an example of theschematic configuration of the system 1 according to the embodiment ofthe present disclosure. Referring to FIG. 4, the system 1 includes abase station 100, a terminal device 200, and a terminal device 300.Here, each of the terminal device 200 and the terminal device 300 isalso called a user.

Note that, although only one terminal device 200 and one terminal device300 are illustrated here for the sake of facilitating understanding, thesystem 1 can of course include a plurality of terminal devices 200and/or a plurality of terminal devices 300.

(1) Base Station 100

The base station 100 is a base station of a cellular system (or a mobilecommunication system). The base station 100 performs radio communicationwith a terminal device (e.g., each of the terminal device 200 and theterminal device 300) positioned within a cell 101 of the base station100. The base station 100, for example, transmits a downlink signal tothe terminal device, and receives an uplink signal from the terminaldevice.

In the embodiment of the present disclosure, in particular, the basestation 100 supports non-orthogonal multiple access (NOMA) as will bedescribed below.

(2) Terminal Device 200

The terminal device 200 can perform communication in a cellular system(or mobile communication system). The terminal device 200 performs radiocommunication with a base station (e.g., the base station 100) of thecellular system. For example, the terminal device 200 receives adownlink signal from the base station, and transmits an uplink signal tothe base station.

In the embodiment of the present disclosure, in particular, the terminaldevice 200 supports non-orthogonal multiple access (NOMA) as will bedescribed below. For example, the terminal device 200 can performinterference cancellation (e.g., removing a signal destined for anotherterminal device by regarding it as an interfering signal). Theinterference cancellation includes, for example, successive interferencecancellation (SIC), parallel interference cancellation (PIC), or thelike.

(3) Terminal Device 300

The terminal device 300 can perform communication in a cellular system(or mobile communication system). The terminal device 300 performs radiocommunication with a base station (e.g., the base station 100) of thecellular system. For example, the terminal device 200 receives adownlink signal from the base station, and transmits an uplink signal tothe base station.

In the embodiment of the present disclosure, in particular, the terminaldevice 300 does not support non-orthogonal multiple access (NOMA) aswill be described below. For example, the terminal device 200 is notcapable of performing interference cancellation (e.g., removing a signaldestined for another terminal device by regarding it as an interferingsignal). For this reason, the terminal device 300 can also be called alegacy terminal in the present specification.

(4) Frequency Band

The base station 100 performs radio communication with a terminal deviceusing one or more frequency bands. For example, the base station 100supports carrier aggregation (CA), and each of the one or more frequencybands is a component carrier (CC). Examples of frequency bands to beused by the base station 100 will be described below with reference toFIG. 5.

FIG. 5 is an illustrative diagram for describing examples of frequencybands to be used by the base station 100. Referring to FIG. 5, a CC 31and a CC 33 are illustrated. The base station 100 performs radiocommunication with a terminal device using, for example, the CC 31 andthe CC 33.

(5) Non-Orthogonal Multiple Access (NOMA)

In the embodiment of the present disclosure, in particular, the basestation 100 and the terminal device 200 support non-orthogonal multipleaccess (NOMA) as described above.

Radio communication of non-orthogonal multiple access is performed indownlink, for example. That is, the base station 100 transmits a signalusing each of a plurality of layers that are to be multiplexed in afrequency band. The terminal device 200 decodes the signal transmittedon at least one of the plurality of layers that are to be multiplexed inthe frequency band. Note that the terminal device 200 can remove asignal transmitted on another layer among the plurality of layers asinterference in interference cancellation.

For example, non-orthogonal multiple access performed here isnon-orthogonal multiple access using power allocation. Morespecifically, for example, the non-orthogonal multiple access isnon-orthogonal multiple access using superposition coding (SPC) (i.e.,SPC-NOMA). An example of this type of non-orthogonal multiple accesswill be described below using FIG. 6.

FIG. 6 is an illustrative diagram for describing an example of thenon-orthogonal multiple access. Referring to FIG. 6, the CC 31 and theCC 33 are illustrated as in FIG. 5. In this example, non-orthogonalmultiple access using SPC is applied to the CC 33, and thus a layer 1and a layer 2 are multiplexed in the CC 33. The base station 100allocates a higher level of electric power to the layer 1 and a lowerlevel of electric power to the layer 2. As an example, the base station100 transmits a signal to the terminal device 200 using the layer 2 inthe CC 33 and transmits a signal to another terminal device (e.g.,another terminal device 200 or the terminal device 300) using the layer1 in the CC 33. In this case, the terminal device 200 removes the signaltransmitted on the layer 1 from the received signal as interference anddecodes the signal transmitted on the layer 2.

Note that radio communication of the above-described non-orthogonalmultiple access may be performed in uplink as well as in downlink.

3. Configuration of Each Device

Now, configurations of the base station 100 and the terminal device 200according to an embodiment of the present disclosure will be describedwith reference to FIGS. 7 and 8.

<3.1. Configuration of Base Station>

First, an example of the configuration of the base station 100 accordingto an embodiment of the present disclosure will be described withreference to FIG. 7. FIG. 7 is a block diagram illustrating the exampleof the configuration of the base station 100 according to an embodimentof the present disclosure. According to FIG. 7, the base station 100includes an antenna unit 110, a radio communication unit 120, a networkcommunication unit 130, a storage unit 140, and a processing unit 150.

(1) Antenna Unit 110

The antenna unit 110 radiates signals output by the radio communicationunit 120 out into space as radio waves. In addition, the antenna unit110 converts radio waves in the space into signals, and outputs thesignals to the radio communication unit 120.

(2) Radio Communication Unit 120

The radio communication unit 120 transmits and receives signals. Forexample, the radio communication unit 120 transmits a downlink signal toa terminal device, and receives an uplink signal from a terminal device.

(3) Network Communication Unit 130

The network communication unit 130 transmits and receives information.For example, the network communication unit 130 transmits information toother nodes, and receives information from other nodes. For example, theother nodes include another base station and a core network node.

(4) Storage Unit 140

The storage unit 140 temporarily or permanently stores a program andvarious data for operation of the base station 100.

(5) Processing Unit 150

The processing unit 150 provides various functions of the base station100. The processing unit 150 includes a selection unit 151, anotification unit 153, a transmission processing unit 155, and areception processing unit 157. Note that the processing unit 150 canfurther include other constituent elements in addition to the aboveconstituent elements. That is, the processing unit 150 can also performoperations other than the operations of the above constituent elements.

Operations of the selection unit 151, the notification unit 153, thetransmission processing unit 155, and the reception processing unit 157will be described below in detail.

<3.2. Configuration of Terminal Device>

First, an example of the configuration of the terminal device 200according to an embodiment of the present disclosure will be describedwith reference to FIG. 8. FIG. 8 is a block diagram illustrating theexample of the configuration of the terminal device 200 according to anembodiment of the present disclosure. According to FIG. 8, the terminaldevice 200 includes an antenna unit 210, a radio communication unit 220,a storage unit 230, and a processing unit 240.

(1) Antenna Unit 210

The antenna unit 210 radiates signals output by the radio communicationunit 220 out into space as radio waves. In addition, the antenna unit210 converts radio waves in the space into signals, and outputs thesignals to the radio communication unit 220.

(2) Radio Communication Unit 220

The radio communication unit 220 transmits and receives signals. Forexample, the radio communication unit 220 receives a downlink signalfrom a base station, and transmits an uplink signal to a base station.

(3) Storage Unit 230

The storage unit 230 temporarily or permanently stores a program andvarious data for operation of the terminal device 200.

(4) Processing Unit 240

The processing unit 240 provides various functions of the terminaldevice 200. The processing unit 240 includes an information acquisitionunit 241, a notification unit 243, a transmission processing unit 245,and a reception processing unit 247. Note that the processing unit 240can further include other constituent elements in addition to the aboveconstituent elements. That is, the processing unit 240 can also performoperations other than the operations of the above constituent elements.

Operations of the information acquisition unit 241, the notificationunit 243, the transmission processing unit 245, and the receptionprocessing unit 247 will be described below in detail.

4. Technical Features

Next, technical features of the embodiment of the present disclosurewill be described with reference to FIGS. 9 to 15.

(1) Selection and Notification of Frequency Band and Layer

The base station 100 (the selection unit 151) selects a frequency bandto which non-orthogonal multiple access is applied and at least onelayer among a plurality of layers that are to be multiplexed in thefrequency band for the non-orthogonal multiple access as a band and alayer to be used for transmission to the terminal device 200. Then, thebase station 100 (the notification unit 153) notifies the terminaldevice 200 of the frequency band and the at least one layer.

(a) Frequency Band

The base station 100 and the terminal device 200 support, for example,carrier aggregation (CA), and the frequency band is a component carrier(CC) for CA. Referring to FIG. 6 again, the frequency band is the CC 33as an example.

(b) Non-Orthogonal Multiple Access and Layer

The non-orthogonal multiple access is non-orthogonal multiple accessusing, for example, power allocation. In this case, the above-describedplurality of layers are a plurality of layers that are to be multiplexedin the above-described frequency band using power allocation.

More specifically, for example, the non-orthogonal multiple access isnon-orthogonal multiple access using SPC.

(c) Selection

(c-1) One Layer

The at least one layer is, for example, one layer among the plurality oflayers. That is, the base station 100 (the selection unit 151) selectsthe frequency band and one layer among the plurality of layers as a bandand a layer to be used for transmission to the terminal device 200.

(c-2) Selection as SCC

The base station 100 (the selection unit 151) selects the frequency bandas, for example, a secondary component carrier (SCC) to be used fortransmission to the terminal device 200, and selects the at least onelayer as a layer to be used for transmission to the terminal device 200in the SCC. In other words, the base station 100 (the selection unit151) selects a CC to be added as an SCC and a layer to be used fortransmission in the SCC when the SCC for the terminal device 200 isadded.

Note that the frequency band may be a CC dedicated as an SCC (i.e., a CCused only as an SCC, not used as a primary component carrier (PCC)).

(c-3) Selection as Band of Handover Destination

The base station 100 (the selection unit 151) may select the frequencyband as a band of a handover destination of the terminal device 200, andselect the at least one layer as a layer to be used for transmission tothe terminal device 200 in the band of the handover destination. Inother words, the base station 100 (the selection unit 151) may select aCC of a handover destination that is a PCC and a layer to be used fortransmission in the PCC at the time of handover of the terminal device200.

(c-4) Example of Selection

Referring to FIG. 6 again, the base station 100 (the selection unit 151)selects the CC 33 and the layer 2 as a band and a layer to be used fortransmission to the terminal device 200 as an example. The base station100 (the selection unit 151) selects the CC 33 and the layer 1 as a bandand a layer to be used for transmission to the terminal device 200 asanother example.

(d) Notification

(d-1) First Example

The base station 100 (the notification unit 153) notifies the terminaldevice 200 of the frequency band and the at least one layer through, forexample, signaling (e.g., radio resource control (RRC) signaling) to theterminal device 200. That is, the base station 100 (the notificationunit 153) notifies the terminal device 200 of the frequency band and theat least one layer included in a signaling message (e.g., an RRCmessage) thereto. As an example, the signaling message is an RRCconnection reconfiguration message.

As a specific process, for example, the notification unit 153 generatesa signaling message that includes band information (informationindicating the frequency band) and layer information (informationindicating the at least one layer). Then, the transmission processingunit 155 performs a transmission process of the signaling message.

(d-2) Second Example

When the frequency band is selected as an SCC, the base station 100 (thenotification unit 153) may notify the terminal device 200 of thefrequency band and the at least one layer included in a media accesscontrol (MAC) control element. The MAC control element may be foractivation of the SCC.

As a specific process, the notification unit 153 may generate an MACcontrol element that includes band information (information indicatingthe frequency band) and layer information (information indicating the atleast one layer). Then, the transmission processing unit 155 may performa transmission process of the MAC control element.

(d-3) Operation of Terminal Device

The terminal device 200 (the information acquisition unit 241) acquiresthe band information (the information indicating the frequency band) andthe layer information (the information indicating the at least onelayer).

The terminal device 200 receives, for example, the signaling messageincluding the band information and the layer information (or the MACcontrol element). Thereby, the terminal device 200 (the informationacquisition unit 241) acquires the band information and the layerinformation.

(e) Others

The terminal device 200 (the notification unit 243) notifies the basestation 100 of, for example, capability information indicating that theterminal device 200 supports the non-orthogonal multiple access.Specifically, for example, the terminal device 200 (the notificationunit 243) notifies the base station 100 of the capability informationincluded in a signaling message (e.g., an RRC message). As an example,the signaling message is a UE capability information message.

As a specific process, for example, the notification unit 243 generatesthe signaling message. Then, the transmission processing unit 155performs a transmission process of the signaling message.

Accordingly, for example, the base station 100 can ascertain theterminal device supporting the non-orthogonal multiple access.

As described above, the base station 100 selects the frequency band andthe at least one layer as a band and a layer to be used for transmissionto the terminal device 200, and notifies the terminal device 200 of thefrequency band and the at least one layer. Accordingly, for example, itis possible to further reduce a burden of scheduling in non-orthogonalmultiple access. More specifically, for example, a layer to be used bythe terminal device 200 is not selected each time a signal istransmitted to the terminal device 200 (i.e., each time scheduling isperformed), but is selected when a frequency band starts being used, andthus a burden of processing performed by the base station 100 can bereduced. In addition, the terminal device 200 is not notified of a layerto be used by the terminal device 200 each time a signal is transmittedto the terminal device 200 (i.e., each time scheduling is performed),but may be notified thereof when a frequency band starts being used, andthus a burden of consuming radio resources can be reduced.

(2) Case of Legacy Terminal (Terminal Device 300)

The base station 100 (the selection unit 151) selects, for example, thefrequency band and a layer among the plurality of layers to whichmaximum power is allocated as a band and a layer to be used fortransmission to the terminal device 300 (i.e., a terminal device notsupporting the non-orthogonal multiple access). Then, the base station100 (the notification unit 153) notifies the terminal device 300 of thefrequency band.

(a) Selection

(a-1) Selection of SCC

The base station 100 (the selection unit 151) selects, for example, thefrequency band as an SCC to be used for transmission to the terminaldevice 300, and selects the layer to which maximum power is allocated asa layer to be used for transmission to the terminal device 300 in theSCC. In other words, the base station 100 (the selection unit 151)selects a CC to be added as an SCC and a layer to be used fortransmission (a layer to which maximum power is allocated) in the SCCwhen the SCC for the terminal device 300 is added.

(a-2) Selection of Band of Handover Destination

The base station 100 (the selection unit 151) may select the frequencyband as a band of a handover destination of the terminal device 300 andselect the layer to which the maximum power is allocated as a layer tobe used for transmission to the terminal device 300 in the band of thehandover destination. In other words, the base station 100 (theselection unit 151) may select a CC of a handover destination as a primacomponent carrier (PCC) and a layer (a layer to which maximum power isallocated) to be used for transmission in the PCC at the time ofhandover of the terminal device 300.

(a-3) Example of Selection

Referring to FIG. 6 again, the base station 100 (the selection unit 151)selects the CC 33 and the layer 1 as a band and a layer to be used fortransmission to the terminal device 300 as an example.

(b) Notification

The base station 100 (the notification unit 153) notifies the terminaldevice 300 of the frequency band as described above. Note that the basestation 100 (the notification unit 153) does not notify the terminaldevice 300 of the layer to which the maximum power is allocated. Thereason for this is that it is neither possible nor necessary for theterminal device 300, which is a legacy terminal, to ascertain the layer.

(b-1) First Example

For example, the base station 100 (the notification unit 153) notifiesthe terminal device 300 of the frequency band through signaling (e.g.,RRC signaling) to the terminal device 300. That is, the base station 100(the notification unit 153) notifies the terminal device 300 of thefrequency band included in a signaling message (e.g., an RRC message)thereto. As an example, the signaling message is an RRC connectionreconfiguration message.

As a specific process, for example, the notification unit 153 generatesa signaling message that includes band information (informationindicating the frequency band). Then, the transmission processing unit155 performs a transmission process of the signaling message.

(b-2) Second Example

When the frequency band is selected as an SCC, the base station 100 (thenotification unit 153) may notify the terminal device 300 of thefrequency band included in an MAC control element. The MAC controlelement may be for activation of the SCC.

As a specific process, the notification unit 153 may generate the MACcontrol element that includes band information (information indicatingthe frequency band). Then, the transmission processing unit 155 mayperform a transmission process of the MAC control element.

(b-3) Operation of Terminal Device

The terminal device 300 acquires, for example, the band information (theinformation indicating the frequency band).

The terminal device 300 receives, for example, the signaling message (orthe MAC control element) that includes the band information. Thereby,the terminal device 300 acquires the band information.

The base station 100 (the selection unit 151) selects, for example, thefrequency band and the layer to which the maximum power is allocated asa band and a layer to be used for transmission to the terminal device300, and notifies the terminal device 300 of the frequency band asdescribed above. Accordingly, backward compatibility, for example, canbe secured. That is, a legacy terminal (the terminal device 300) canperform radio communication even in a frequency band to whichnon-orthogonal multiple access is applied. More specifically, even whena signal of another layer (i.e., an interfering signal) is included in areceived signal, for example, the legacy terminal (the terminal device300) can decode a signal destined for itself (e.g., without performinginterference cancellation) because a higher level of electric power isallocated to the signal to the legacy terminal.

Note that the base station 100 (the selection unit 151) may of courseselect the frequency band and the layer to which the maximum power isallocated as a band and a layer to be used for transmission to theterminal device 200 (or another the terminal device 200 (which is notillustrated)), rather than the terminal device 300.

(3) Transmission and Reception on Layer

(a) Transmission by Base Station 100

The base station 100 (the transmission processing unit 155) transmits asignal in the frequency band. More specifically, the base station 100(the transmission processing unit 155) transmits a signal using each ofa plurality of layers in the frequency band.

In particular, the base station 100 (the transmission processing unit155) transmits the signal to the terminal device 200 using the at leastone layer (a layer to be used for transmission to the terminal device200) in the frequency band.

The base station 100 (the transmission processing unit 155) transmits asignal to the terminal device 300 using, for example, the layer to whichthe maximum power is allocated in the frequency band.

Referring to FIG. 6 again, the base station 100 transmits a signal tothe terminal device 200 using the layer 2 and transmits a signal to theterminal device 300 using the layer 1 in the CC 33, as an example.

Note that, in the present specification, “the transmission processingunit 155 transmits a signal to a terminal device” means “thetransmission processing unit 155 performs a transmission process oftransmitting a signal to a terminal device.” The transmission processmentioned here includes, for example, digital processing of a physicallayer.

(b) Reception by Terminal Device 200

The terminal device 200 (the information acquisition unit 241) acquiresthe band information (the information indicating the frequency band) andthe layer information (the information indicating the at least onelayer) as described above. Then, the terminal device 200 (the receptionprocessing unit 247) decodes the signal transmitted on the at least onelayer (i.e., a layer to be used for transmission to the terminal device200) in the frequency band.

The at least one layer (i.e., a layer to be used for transmission to theterminal device 200) is, for example, one layer among the plurality oflayers.

In a first case, for example, the one layer is a layer to which maximumpower is allocated among the plurality of layers. In this case, theterminal device 200 decodes a signal transmitted on the one layer from,for example, a received signal (i.e., a multiplexed signal).

In a second case, for example, the one layer is a layer different fromthe layer to which the maximum power is allocated among the plurality oflayers. In this case, for example, the terminal device 200 generates asignal transmitted on another layer (e.g., a layer to which a higherlevel of electric power is allocated than the one layer) as aninterference replica signal and removes the interference replica signalfrom a received signal. Then, the terminal device 200 decodes a signalof the received signal transmitted on the one layer after the removal.

Referring to FIG. 6 again, the base station 100 transmits a signal tothe terminal device 200 using the layer 2 in the CC 33, as an example.In this case, the terminal device 200 generates a signal transmitted onthe layer 1 in the CC 33 as an interference replica signal, and removesthe interference replica signal from a received signal of the CC 33.Then, the terminal device 200 decodes the signal transmitted on thelayer 2 in the CC 33 from the received signal after the removal.

(c) Reception by Legacy Terminal (Terminal Device 300)

The terminal device 300 acquires the band information (the informationindicating the frequency band) as described above. Then, the terminaldevice 300 decodes a signal transmitted in the frequency band(practically, a signal transmitted on the layer to which maximum poweris allocated). Note that the terminal device 200 is a legacy terminal (aterminal device that does not support the non-orthogonal multipleaccess) and decodes a signal regardless of a layer.

(d) Signal Transmitted on Each Layer

(d-1) Signal of Physical Data Channel

The base station 100 (the transmission processing unit 155) transmits,for example, a signal of a physical data channel on each of theplurality of layers in the frequency band.

The physical data channel is a channel used for transmission of a datasignal (and a control signal). For this reason, the signal of thephysical data channel is a data signal (and a control signal).

As an example, the physical data channel is a physical downlink sharedchannel (PDSCH). However, the physical data channel is not limitedthereto, and may have another name in a future standard.

Thereby, for example, the data signal is multiplexed and thus the basestation 100 can transmit more data signals.

(d-2) Signal of Physical Control Channel

The base station 100 (the transmission processing unit 155) transmits,for example, a signal of a physical control channel in the frequencyband.

The physical control channel is a channel used for transmission of acontrol signal. For this reason, the signal of the physical data channelis a control signal. More specifically, the control signal is, forexample, a signal of downlink control information (DCI).

As an example, the physical control channel is a physical downlinkcontrol channel (PDCCH). However, the physical control channel is notlimited thereto, and may have another name in a future standard.

Transmission on One Layer

The base station 100 (the transmission processing unit 155) transmits,for example, the signal of the physical control channel using one layeramong the plurality of layers in the frequency band.

The signal of the physical control channel includes, for example, asignal of scheduling information with respect to each of the pluralityof layers. This can also be called cross-layer scheduling. In addition,the one layer among the plurality of layers is, for example, a layer towhich maximum transmission power among the plurality of layers isallocated. Examples of signals transmitted on layers by the base station100 will be described below with reference to FIGS. 9 and 10.

FIG. 9 is an illustrative diagram for describing a first example of asignal transmitted on each layer by the base station 100. Referring toFIG. 9, the layer 1 and the layer 2 of the CC 33 are illustrated. Inthis example, a first to a third symbols among subframes are symbols inwhich a PDCCH is deployed in the layer 1, and null symbols in the layer2. That is, the base station 100 transmits a signal of the PDCCH on thelayer 1 and transmits no signal on the layer 2 in the first to the thirdsymbols. Accordingly, communication quality of the layer 1 can beenhanced. In particular, the signal of the PDCCH transmitted on thelayer 1 includes signals of scheduling information for the layer 1 andthe layer 2. In addition, a 4^(th) to a 14^(th) symbols among thesubframes of the layer 1 and the layer 2 are symbols in which a PDSCH isdeployed in the layer 1 and the layer 2. That is, the base station 100transmits a signal of the PDSCH on the layer 1 and the layer 2 in the4^(th) to the 14^(th) symbols.

FIG. 10 is an illustrative diagram for describing a second example of asignal transmitted on each layer by the base station 100. Referring toFIG. 10, the layer 1 and the layer 2 of the CC 33 are illustrated.Particularly in this example, the first to the third symbols amongsubframes are not null symbols in the layer 2 but symbols in which aPDSCH is deployed. That is, the base station 100 transmits a signal ofthe PDCCH on the layer 1 and transmits a signal of the PDSCH on thelayer 2 in the first to the third symbols. Accordingly, the base station100 can transmit more data signals.

Note that the base station 100 (the transmission processing unit 155)may transmit a signal of the physical control channel withoutmultiplexing in the frequency band, instead of transmitting the signalof the physical control channel on the one layer in the frequency band.

According to the first example described above, the terminal device 200can acquire the scheduling information more easily. More specifically,for example, the terminal device 200 can acquire the schedulinginformation without interference cancellation, regardless of a layer tobe used for transmission to the terminal device 200.

Transmission on Each Layer

The base station 100 (the transmission processing unit 155) may transmita signal of the physical control channel on each of the plurality oflayers in the frequency band. An example of a signal transmitted on eachlayer by the base station 100 will be described below with reference toFIG. 11.

FIG. 11 is an illustrative diagram for describing a third example of asignal transmitted on each layer by the base station 100. Referring toFIG. 11, the layer 1 and the layer 2 of the CC 33 are illustrated. Inthis example, the first to the third symbols among subframes are symbolsin which a PDCCH is deployed in the layer 1 and the layer 2. That is,the base station 100 transmits signals of the PDCCH on the layer 1 andthe layer 2 in the first to the third symbols. The signal of the PDCCHtransmitted on the layer 1 includes a signal of scheduling informationof the layer 1, and the signal of the PDCCH transmitted on the layer 2includes a signal of scheduling information of the layer 2. In addition,the 4^(th) to a 14^(th) symbols among the subframes are symbols in whicha PDSCH is deployed in the layer 1 and the layer 2. That is, the basestation 100 transmits signals of the PDSCH on the layer 1 and the layer2 in the 4^(th) to a 14^(th) symbols.

According to the second example described above, the schedulinginformation can be more simplified.

Cross-Carrier Scheduling

The base station 100 (the transmission processing unit 155) may nottransmit the signal of the physical control channel in the frequencyband. Instead, the base station 100 (the transmission processing unit155) may transmit the signal of the physical control channel in anotherfrequency band and the signal may include the signal of the schedulinginformation for each of the plurality of layers. That is, cross-carrierscheduling may be performed. An example of a signal transmitted on eachlayer by the base station 100 will be described below with reference toFIG. 12.

FIG. 12 is an illustrative diagram for describing a fourth example of asignal transmitted on each layer by the base station 100. Referring toFIG. 12, the CC 31 and the CC 33 are illustrated, and the layer 1 andthe layer 2 of the CC 33 are also illustrated. In this example, a PDCCHis deployed in neither the layer 1 nor the layer 2 in the CC 33.Instead, a PDCCH is deployed in the CC 31, and scheduling information ofthe layer 1 and the layer 2 of the CC 33 is transmitted in the PDCCH.That is, the base station 100 transmits a signal of the PDCCH in thefirst to the third symbols of the CC 31, and the signal includes thesignal of the scheduling information of the layer 1 and the layer 2 ofthe CC 33. Note that all symbols of the subframes in the CC 33 aresymbols in which the PDSCH is deployed in the layer 1 and the layer 2.That is, the base station 100 transmits the signal of the PDSCH on thelayer 1 and the layer 2 in all the symbols.

(d-3) Other Signals

Further, the base station 100 transmits, for example, other signals inthe frequency band as well.

Other Signals

The other signals include, for example, a synchronization signal. Forexample, the synchronization signal includes a primary synchronizationsignal (PSS) and a secondary synchronization signal (SSS).

The other signals include, for example, a signal of a physical broadcastchannel (PBCH).

First Example

As a first example, the base station 100 (the transmission processingunit 155) transmits the other signals on one layer among the pluralityof layers in the frequency band. Examples of signals transmitted on eachlayer by the base station 100 will be described below with reference toFIGS. 13 and 14.

FIG. 13 is an illustrative diagram for describing a fifth example of asignal transmitted on each layer by the base station 100. Referring toFIG. 13, the layer 1 and the layer 2 of the CC 33 are illustrated. Inthis example, the base station 100 transmits signals of a PSS, a SSS,and a PBCH on the layer 1 in the CC 33. On the other hand, the basestation 100 transmits none of the signals of the PSS, the SSS, and thePBCH on the layer 2 in the CC 33. Particularly in this example, the basestation 100 transmits no signal on the layer 2 using radio resources forthe PSS and SSS and the PBCH. Accordingly, communication quality of thelayer 1 can be enhanced. More specifically, for example, quality of thePSS, the SSS, and the PBCH can be enhanced.

FIG. 14 is an illustrative diagram for describing a sixth example of asignal transmitted on each layer by the base station 100. Referring toFIG. 14, the layer 1 and the layer 2 of the CC 33 are illustrated.Particularly in this example, the base station 100 transmits a signal ofa PDSCH on the layer 2 using radio resources for the PSS, the SSS, andthe PBCH. Accordingly, the base station 100 can transmit more datasignals.

Note that the base station 100 (the transmission processing unit 155)may transmit the other signals without multiplexing in the frequencyband, instead of transmitting the other signals on the one layer in thefrequency band.

Second Example

As a second example, the base station 100 (the transmission processingunit 155) may transmit the other signals (e.g., a synchronization signaland/or a signal of a PBCH) on each of the plurality of layers in thefrequency band. Accordingly, for example, each layer can be treated asan independent CC.

(e) Others

(e-1) Bandwidth of Each Layer

Bandwidths of frequency resources to be used may be different between atleast two layers included in the plurality of layers. A specific examplethereof will be described with reference to FIG. 15 below.

FIG. 15 is an illustrative diagram for describing examples of bandwidthsof respective layers. Referring to FIG. 15, the CC 31 and the CC 33 areillustrated. For example, the entire CC 33 is used for the layer 1 ofthe CC 33 and a partial band 35 which is a part of the CC 33 is used forthe layer 2 of the CC 33.

(e-2) Treatment of Layer

Each of the plurality of layers may be treated like a component carrier.For example, system information may be transmitted on each of theplurality of layers. In addition for example, each of the plurality oflayers may be activated or deactivated for the terminal device 200.

(4) Re-Selection and Notification of Layer

The base station 100 (the selection unit 151) re-selects, for example,another layer among the plurality of layers as a layer to be used fortransmission to the terminal device 200. Then, the base station 100 (thenotification unit 153) notifies the terminal device 200 of the otherlayer. That is, the base station 100 changes only the layer withoutchanging the frequency band (e.g., a CC), and notifies the terminaldevice 200 of the changed layer. The re-selection of the layer (thechange of the layer) can also be called handover of layers.

Referring to FIG. 6 again, the terminal device 200 uses the layer 2 ofthe CC 33 as an example. In this case, the base station 100 re-selectsthe layer 1 of the CC 33 as a layer to be used for transmission to theterminal device 200. Then, the base station 100 notifies the terminaldevice 200 of the layer 1.

The base station 100 re-selects, for example, another layer on the basisof a result of measurement by the terminal device 200. Morespecifically, for example, when communication quality of the terminaldevice 200 deteriorates, the base station 100 re-selects a layer towhich a higher level of electric power is allocated (e.g., the layer 1of the CC3 illustrated in FIG. 6) as a layer to be used for transmissionto the terminal device 200. On the other hand, for example, whencommunication quality of the terminal device 200 is improved, the basestation 100 re-selects a layer to which a lower level of electric poweris allocated (e.g., the layer 2 of the CC3 illustrated in FIG. 6) as alayer to be used for transmission to the terminal device 200.

Accordingly, for example, it is possible for the terminal device 200 toflexibly use layers.

5. Process Flow

Next, technical features of the embodiment of the present disclosurewill be described with reference to FIGS. 16 and 17.

(1) Overall Process

FIG. 16 is a sequence diagram illustrating an example of a schematicflow of an overall process according to the embodiment of the presentdisclosure.

The base station 100 transmits a UE capability enquiry message to theterminal device 200 (S401).

The terminal device 200 transmits a UE capability information message(S403). The UE capability information message includes capabilityinformation indicating that the terminal device 200 supportsnon-orthogonal multiple access (NOMA). The terminal device 200 notifiesthe base station 100 of the capability information in this manner, forexample.

The base station 100 selects a CC to which the non-orthogonal multipleaccess is applied and at least one layer among a plurality of layersthat are to be multiplexed in the CC for the non-orthogonal multipleaccess as a band and a layer to be used for transmission to the terminaldevice 200 (S405).

The base station 100 transmits an RRC connection reconfiguration messageto the terminal device 200 (S407). The RRC connection reconfigurationmessage includes band information indicating the CC and layerinformation indicating the at least one layer. The base station 100notifies the terminal device 200 of the CC and the at least one layer inthis manner, for example.

The terminal device 200 acquires the band information and the layerinformation, and transmits an RRC connection reconfiguration completemessage to the base station 100 (S409).

The base station 100 transmits a signal of a PDCCH in the CC (S411). Forexample, the base station 100 transmits the signal of the PDCCH on onelayer among the plurality of layers in the CC.

The terminal device 200 acquires downlink control information (DCI) bydecoding the signal of the PDCCH (S413). The downlink controlinformation includes scheduling information. The scheduling informationis scheduling information of the at least one layer of the CC.

The base station 100 transmits a signal of a PDSCH on each of theplurality of layers in the CC (S415). For example, the base station 100transmits the signal to the terminal device 200 on the at least onelayer in the CC.

The terminal device 200 decodes the signal transmitted on the at leastone layer in the CC (S417). Then, the terminal device 200 transmits anacknowledgement (ACK)/a negative acknowledgement (NACK) to the basestation 100 (S419).

(2) Process of Terminal Device 200

FIG. 17 is a sequence diagram illustrating an example of a schematicflow of a process of the terminal device 200 according to the embodimentof the present disclosure. The process corresponds to Steps S413 andS417 illustrated in FIG. 16. The process can be performed for eachsubframe.

The terminal device 200 (the information acquisition unit 241) acquiresthe DCI (S431).

When radio resources are allocated to the terminal device 200 (S433:YES), if a layer to be used for transmission to the terminal device 200is a layer to which maximum power is allocated (S435: YES), the terminaldevice 200 (the reception processing unit 247) decodes a signaltransmitted on the layer (S437). Then, the process ends.

On the other hand, if the layer to be used for transmission to theterminal device 200 is not a layer to which maximum power is allocated(S435: NO), the terminal device 200 (the reception processing unit 247)decodes a signal transmitted on the at least one layer while performinginterference cancellation (S439). For example, the terminal device 200(the reception processing unit 247) generates a signal transmitted onanother layer as an interference replica signal in the interferencecancellation, and removes the interference replica signal from receptionpower of the CC. Then, the process ends.

When no radio resources are allocated to the terminal device 200 (S433:NO), the process ends.

Note that non-orthogonal multiple access using power allocation (e.g.,SPC-NOMA) is not applied at all times, and may be applied as necessary.In that case, the DCI may include information indicating whether thenon-orthogonal multiple access is applied (e.g., a bit), and theterminal device 200 may determine whether the non-orthogonal multipleaccess is applied (e.g., immediately after Step S433). If thenon-orthogonal multiple access is applied, the process may proceed toStep S435, or if the non-orthogonal multiple access is not applied, theprocess may proceed to Step S437.

6. Modified Example

Next, a modified example of the embodiment of the present disclosurewill be described with reference to FIGS. 18 to 25.

In the modified examples of the embodiment of the present disclosure,the plurality of layers include a first layer of which a length of atime frame is a first length and a second layer of which a length of atime frame is a second length that is shorter than the first length.That is, there are time frames having different lengths between at leasttwo layers among the plurality of layers. Accordingly, for example,latency can be further shortened.

(1) Time Frame

(a) Example of Time Frame

The time frame is, for example, a cycle of allocation of radioresources. More specifically, for example, the time frame is a subframe.

(b) Length of Time Frame

The first length is, for example, equal to a length of a time frame ofanother frequency band to which the non-orthogonal multiple access isnot applied, and the second length is shorter than the length of thetime frame of the other frequency band. That is, the time frame of thefirst layer has an equal length to that of a normal time frame, and thetime frame of the second layer has a shorter length than that of thenormal time frame.

The first length is, for example, an integral multiple of the secondlength. In addition, for example, each symbol included in the time frameof the first layer has an equal length to that of each symbol includedin the time frame of the second layer. Examples of time frames will bedescribed below with reference to FIGS. 18 and 19.

FIG. 18 is an illustrative diagram for describing a general frameconfiguration. Referring to FIG. 18, a radio frame is illustrated. Theradio frame has, for example, a length of 10 ms and includes 10subframes. In addition, each subframe has, for example, a length of 1 msand includes 14 symbols.

FIG. 19 is an illustrative diagram for describing an example of a frameconfiguration according to the modified example. Referring to FIG. 19,the layer 1 and the layer 2 of the CC 33 are illustrated. In thisexample, the layer 1 has a general frame configuration described withreference to FIG. 18. That is, the radio frame of the layer 1 has alength of 10 ms and includes 10 subframes. In addition, each subframe ofthe layer 1 has a length of 1 ms and includes 14 symbols. Meanwhile, thelayer 2 has a frame configuration that is different from the generalframe configuration. Specifically, the radio frame of the layer 2 has alength of 10 ms and includes 20 subframes. In addition, each subframe ofthe layer 2 has a length of 0.5 ms and includes 7 symbols. As describedabove, the lengths of subframes (cycles of allocation of radioresources) are different between the layer 1 and the layer 2.Furthermore, the CC 31 (not illustrated) that is different from the CC33 also has a general frame configuration described with reference toFIG. 18, like the layer 1. That is, the length of the subframes of thelayer 1 is equal to that of subframes of the CC 31.

Note that, since the length of each subframe of the layer 2 is shorter,the length of radio resources of the layer 2 is shorter in the timedirection. As an example, although a pair of two resource blocks thatare arranged in the time direction are allocated to the layer 1, onlyone resource block is allocated to the layer 2 in the time direction.

As described above, the layers have different lengths of time frames.Accordingly, for example, a unit of radio resources allocated to atleast one layer decreases. The unit of radio resources allocated ischanged, for example, from a pair of resource blocks to a singleresource block. For this reason, radio resources can be allocated tomore terminal devices within a certain period of time. As a result,legacy can be further shortened.

Note that, although the example in which the length of the radio frameis uniform regardless of a length of a subframe has been described, themodified example of the embodiment of the present disclosure is notlimited thereto. The radio frame may include 10 subframes, for example,regardless of a length of a subframe. Specifically, when a length of asubframe is 0.5 ms, a length of a radio frame may be 5 ms.

(2) Real-Time Property of Data and Layer

The base station 100 (the transmission processing unit 155) transmits,for example, a signal of data having a lower real-time property on thefirst layer and a signal of data having a higher real-time property onthe second layer in the frequency band.

Referring to FIG. 19 again, the base station 100 transmits a signal ofdata having a lower real-time property on the layer 1 and a signal ofdata having a higher real-time property on the layer 2 in the CC 33 asan example. The data having the higher real-time property is, forexample, audio data or video data.

Accordingly, latency of data having a higher real-time property can beshortened, for example.

Note that the base station 100 (the processing unit 150) may determine areal-time property of data on the basis of QoS Class Identifier (QCI).The QCI may be QCI of a bearer corresponding to the data. The QCI may beassociated with characteristics of quality of service (QoS) as describedbelow.

TABLE 1 Resource Packet Delay Packet Error QCI Type Priority Budget LossRate Example Services 1 GBR 2 100 msec 10⁻² Conversational Voice 2 4 150msec 10⁻³ Conversational Voice (Live Streaming) 3 3  50 msec 10⁻³ RealTime Gaming 4 5 300 msec 10⁻⁶ Non-Conversational Video (BufferedStreaming) 5 Non-GBR 1 100 msec 10⁻⁶ IMS Signaling 6 6 300 msec 10⁻⁶Video (Buffered Streaming), TCP Based Applications 7 7 100 msec 10⁻³Voice, Video (Live Streaming), Interactive Gaming 8 8 300 msec 10⁻⁶Video (Buffered Streaming), TCP Based Applications 9 9 300 msec 10⁻⁶Video (Buffered Streaming), TCP Based Applications

As a first example, the base station 100 may determine data to have ahigh real-time property when a resource type associated with the QCI isGuaranteed Bit Rate (GBR). As a second example, the base station 100 maydetermine data to have a high real-time property when priorityassociated with the QCI is equal to or lower than a predetermined value(or is lower than the predetermined value) (i.e., priority is high). Asa third example, the base station 100 may determine data to have a highreal-time property when a Packet Delay Budget associated with the QCI isequal to or lower than a predetermined value (or is lower than thepredetermined value) (i.e., a requirement for a delay is strict). As afourth example, the base station 100 may determine data to have a highreal-time property when a packet error loss rate associated with the QCIis higher than or equal to a predetermined value (or exceeds thepredetermined value) (i.e., a certain degree of packet loss is allowed).As a fifth example, the base station 100 may determine data to have ahigh real-time property when the QCI a predetermined QCI. A frequencyband and/or a layer can be more easily selected through thedetermination of a real-time property described above.

(3) Throughput/Data Size and Layer

The base station 100 (the transmission processing unit 155) may transmita signal of information in a larger size on the first layer and a signalof information in a smaller size on the second layer in the frequencyband. As an example, the information in the larger size may be data in alarger size, and information in the smaller size may be controlinformation of data in a smaller size. Accordingly, the radio resourcescan be used more efficiently.

The base station 100 (the transmission processing unit 155) may transmita signal of data that requires a higher throughput on the first layerand a signal of data that requires a lower throughput on the secondlayer in the frequency band. Accordingly, a high throughput can begained for the data that requires a higher throughput.

(4) Signal Transmitted on Each Layer

(a) Signal of Physical Data Channel

In the modified example, the base station 100 (the transmissionprocessing unit 155) transmits, for example, a signal of a physical datachannel on each of the plurality of layers in the frequency band.

(b) Signal of Control Channel

In the modified example, the base station 100 (the transmissionprocessing unit 155) transmits, for example, a signal of a physicalcontrol channel in the frequency band.

(b-1) Transmission on One Layer

Also in the modified example, for example, the base station 100 (thetransmission processing unit 155) transmits the signal of the physicalcontrol channel on one layer among the plurality of layers in thefrequency band. In addition, the signal of the physical control channelincludes, for example, a signal of scheduling information with respectto each of the plurality of layers. Furthermore, the one layer among theplurality of layers is, for example, a layer to which maximumtransmission power is allocated among the plurality of layers. Examplesof signals transmitted on each layer by the base station 100 will bedescribed with reference FIGS. 20 and 21.

FIG. 20 is an illustrative diagram for describing a first example of asignal transmitted on each layer by the base station 100 according tothe modified example. Referring to FIG. 20, the layer 1 and the layer 2of the CC 33 are illustrated. In this example, a length of a subframe ofthe layer 2 (i.e., a length of each of a first subframe and a secondsubframe of the layer 2) is half a length of a subframe of the layer 1.In addition, in this example, a first to a third symbols among thesubframes of the layer 1 are symbols in which a PDCCH is deployed, and afirst to a third symbols in the first subframe of the layer 2 are nullsymbols. That is, the base station 100 transmits a signal of the PDCCHin the first to the third symbols of the subframe in the layer 1, andtransmits no signal in the first to the third symbols of the firstsubframe in the layer 2. Accordingly, communication quality of the layer1 can be enhanced. The signal of the PDCCH transmitted on the layer 1includes a signal of scheduling information with respect to the layer 1and the layer 2. In particular, the signal of the PDCCH transmitted onthe layer 1 includes a signal of scheduling information of the twosubframes of the layer 2. Furthermore, a 4^(th) to a 14^(th) symbols ofthe subframe in the layer 1 are symbols in which a PDSCH is deployed,and a 4^(th) to a 7^(th) symbols of the first frame and all symbols ofthe second subframe in the layer 2 are symbols in which the PDSCH isdeployed. That is, the base station 100 transmits the signal of thePDSCH in the 4^(th) to the 14^(th) symbols of the subframe in the layer1, and transmits the signal of the PDSCH in the 4^(th) to the 7^(th)symbols of the first subframe and all the symbols of the second subframein the layer 2.

FIG. 21 is an illustrative diagram for describing a second example of asignal transmitted on each layer by the base station 100 according tothe modified example. Referring to FIG. 21, the layer 1 and the layer 2of the CC 33 are illustrated. In this example, in particular, the firstto the third symbols of the first subframe of the layer 2 are not nullsymbols, but symbols in which the PDSCH is deployed. That is, the basestation 100 transmits the signal of the PDCCH in the first to the thirdsymbols of the subframe in the layer 1, and transmits the signal of thePDSCH in the first to the third symbols of the first subframe in thelayer 2. Accordingly, the base station 100 can transmit more datasignals.

Note that the base station 100 (the transmission processing unit 155)may transmit a signal of the physical control channel withoutmultiplexing in the frequency band, instead of transmitting the signalof the physical control channel on the one layer in the frequency band.

According to the first example, the terminal device 200 can acquire thescheduling information more easily. More specifically, the terminaldevice 200 can acquire the scheduling information without interferencecancellation, for example, regardless of a layer to be used fortransmission to the terminal device 200.

(a-2) Transmission on Each Layer

Also in the modified example, the base station 100 (the transmissionprocessing unit 155) may transmit the signal of the physical controlchannel on each of the plurality of layers in the frequency band. Anexample of a signal transmitted on each layer by the base station 100will be described below with reference to FIG. 22.

FIG. 22 is an illustrative diagram for describing a third example of asignal transmitted on each layer by the base station 100 according tothe modified example. Referring to FIG. 22, the layer 1 and the layer 2of the CC 33 are illustrated. In this example, a length of a subframe ofthe layer 2 (i.e., a length of each of a first subframe and a secondsubframe of the layer 2) is half a length of a subframe of the layer 1.In addition, in this example, a first to a third symbols of each of thesubframe of the layer 1 and the first and the second subframes of thelayer 2 are symbols in which a PDCCH is deployed. That is, the basestation 100 transmits the signal of the PDCCH in the first to the thirdsymbols of the subframe in the layer 1, and transmits the signal of thePDCCH in the first to the third symbols of the first subframe and thefirst to the third symbols of the second subframe in the layer 2. Thesignal of the PDCCH transmitted on the layer 1 includes a signal ofscheduling information with respect to the layer 1. Moreover, the signalof the PDCCH transmitted in the first subframe of the layer 2 includes asignal of scheduling information with respect to the first subframe, andthe signal of the PDCCH transmitted in the second subframe of the layer2 includes a signal of scheduling information with respect to the secondsubframe. A 4^(th) to a 14^(th) symbols of the subframe in the layer 1are symbols in which a PDSCH is deployed, and a 4^(th) to a 7^(th)symbols of each of the first and the second subframes in the layer 2 aresymbols in which a PDSCH is deployed. That is, the base station 100transmits the signal of the PDSCH in the 4^(th) to the 14^(th) symbolsof the subframe in the layer 1, and transmits the signal of the PDSCH inthe 4^(th) to the 7^(th) symbols of each of the first and secondsubframes in the layer 2.

According to the second example described above, the schedulinginformation can be more simplified.

(a-3) Cross-Frame Scheduling

In the modified example, the base station 100 (the transmissionprocessing unit 155) may transmits a signal of a physical controlchannel on each of the plurality of layers in the frequency band. Thethird example is the same as the second example in this point. In thethird example, in particular, the base station 100 (the transmissionprocessing unit 155) may transmit a signal of a physical control channelin one time frame among a plurality of time frames in the second layer(i.e., the layer having a shorter time frame). The signal of thephysical control channel transmitted in the one time frame includes asignal of scheduling information with respect to each of the pluralityof time frames. This can be called cross-frame scheduling. An example ofa signal transmitted on each layer by the base station 100 will bedescribed with reference to FIG. 23.

FIG. 23 is an illustrative diagram for describing a fourth example of asignal transmitted on each layer by the base station 100 according tothe modified example. Referring to FIG. 23, the layer 1 and the layer 2of the CC 33 are illustrated. In this example, in particular, a first tothe third symbols of the second subframe of the layer 2 are symbols inwhich a PDSCH is deployed, not a PDCCH. That is, the base station 100transmits the signal of the PDSCH, not the PDCCH, in the first to thethird symbols of the second subframe in the layer 2. Furthermore,particularly in this example, the signal of the PDCCH transmitted in thefirst subframe of the layer 2 includes a signal of schedulinginformation of the first subframe as well as a signal of schedulinginformation of the second subframe.

According to the third example, for example, the base station 100 cantransmit more data signals.

(a-4) Cross-Carrier Scheduling

In the modified example, the base station 100 (the transmissionprocessing unit 155) may not transmit a signal of a physical controlchannel in the frequency band. Instead, the base station 100 (thetransmission processing unit 155) may transmit the signal of thephysical control channel in another frequency band, and the signal mayinclude a signal of scheduling information with respect to each of theplurality of layers. That is, cross-carrier scheduling may be performed.An example of a signal transmitted on each layer by the base station 100will be described below with reference to FIG. 24.

FIG. 24 is an illustrative diagram for describing a fifth example of asignal transmitted on each layer by the base station 100 according tothe modified example. Referring to FIG. 24, the CC 31 and the CC 33 areillustrated, and the layer 1 and the layer 2 of the CC 33 are furtherillustrated. In this example, a length of a subframe of the layer 2 ofthe CC 33 (i.e., a length of each of the first subframe and the secondsubframe of the layer 2) is half a length of the subframe of the layer 1of the CC 33. The length of the subframe of the layer 1 of the CC 33 isequal to a length of a subframe of the CC 31. In addition, in thisexample, a PDCCH is deployed in neither the layer 1 nor the layer 2 ofthe CC 33. Instead, a PDCCH is deployed in the CC 31, and schedulinginformation of the layer 1 and the layer 2 of the CC 33 is transmittedin the PDCCH. That is, the base station 100 transmits a signal of thePDCCH in a first to a third symbols of the CC 31, and the signalincludes a signal of the scheduling information of the layer 1 and thelayer 2 of the CC 33. Note that all symbols of the subframe of the layer1 and all symbols of the first and the second subframes of the layer 2of the CC 33 are symbols in which a PDSCH is deployed. That is, the basestation 100 transmits a signal of the PDSCH in all the symbols of thelayer 1 and the layer 2.

(b) Other Signals

Further, for example, the base station 100 also transmits another signal(e.g., a synchronization signal and/or a signal of a PBCH) in thefrequency band. Description of this point is as described above.

(5) Others

The base station 100 may alter the length of the time frame of thesecond layer. For example, the base station 100 may alter the length ofthe time frame of the second layer dynamically or semi-statically. Inaddition, the base station 100 may also alter a length of a time frameof another layer among the plurality of layers. An example of analteration of a length of a time frame will be described below withreference to FIG. 25.

FIG. 25 is an illustrative diagram for describing an example of analteration of a length of a time frame. Referring to FIG. 25, two radioframes are illustrated. A first radio frame includes, for example, 20subframes each of which has a length of 0.5 ms. The base station 100alters the length of the subframe from 0.5 ms to 1 ms after an end ofthe first radio frame. Thus, a second radio frame includes 10 subframeseach of which has a length of 1 ms.

7. Another Embodiment

Next, another embodiment will be described with reference to FIG. 26.

<7.1. Technical Problem>

First, a technical problem according to the other embodiment will bedescribed.

There are a variety of requirements for a cellular system. One of therequirements is latency. Latency means a time taken to perform, forexample, a round-operation from transmission of data by a transmissiondevice to reception of an ACK/NACK by the transmission device (a delaytime). Alternatively, latency may mean a time taken to perform around-operation to complete transmission and reception of one transportblock (TB), or a time taken to perform a round-operation to completetransmission and reception of one packet (e.g., IP packet) of ahigher-order layer. A real-time property may not be secured if latencyis long, for example, and thus it is desirable in a cellular system tofurther shorten latency.

Therefore, it is desirable to provide a mechanism that can furthershorten latency in cellular system.

<7.2. Technical Feature>

Next, a technical feature of the other embodiment will be described withreference to FIG. 26.

In the other embodiment, the base station 100 transmits a signal in afirst frequency band and a second frequency band, and a time frame ofthe second frequency band is shorter than a time frame of the firstfrequency band. For example, a length of the time frame of the firstfrequency band is a first length, and a length of the time frame of thesecond frequency band is a second length that is shorter than the firstlength. That is, lengths of time frames are different between thefrequency bands. Accordingly, for example, latency can be furthershortened.

(1) Frequency Bands

Each of the first frequency band and the second frequency band is, forexample, a component carrier.

Note that the base station 100 may of course use a frequency band (e.g.,a component carrier) in addition to the first frequency band and thesecond frequency band.

(2) Time Frame

(a) Example of Time Frame

The time frames each is, for example, a cycle of allocation of radioresources. More specifically, for example, the time frames aresubframes.

(b) Length of Time Frame

The time frame of the first frequency band is, for example, has an equallength to a length of a normal time frame, and the time frame of thesecond frequency band is shorter than that of the normal time frame.

The first length (the length of the time frame of the first frequencyband) is, for example, an integral multiple of the second length (thelength of the time frame of the second frequency band). In addition,each symbol included in the time frame of the first frequency band has,for example, an equal length to that of each symbol included in the timeframe of the second frequency band. An example of time frames will bedescribed below with reference to FIG. 26.

FIG. 26 is an illustrative diagram for describing an example of a frameconfiguration according to the other embodiment. Referring to FIG. 26, aCC 31 and a CC 33 are illustrated. In this example, the CC 31 has thegeneral frame configuration described with reference to FIG. 18. Thatis, a radio frame of the CC 31 has a length of 10 ms and includes 10subframes. In addition, each subframe of the CC 31 has a length of 1 msand includes 14 symbols. Meanwhile, the CC 33 has a frame configurationthat is different from the general frame configuration. Specifically, aradio frame of the CC 33 has a length of 10 ms and includes 20subframes. In addition, each subframe of the CC 33 has a length of 0.5ms and includes 7 symbols. As described above, the lengths of eachsubframe (a cycle of allocation of radio resources) are differentbetween the CC 31 and the CC 33.

Note that, since a time frame of the CC 33 is shorter, radio resourcesof the CC 33 are accordingly shorter in the time direction. As anexample, although a pair of two resource blocks arranged in the timedirection are allocated to the CC 31, only one resource block isallocated to CC 33 in the time direction.

As described above, lengths of time frames are different between thefrequency bands (e.g., CCs). Accordingly, for example, a unit of radioresources allocated to at least one frequency band is small. Forexample, radio resources allocated are changed, for example, from a pairof resource blocks to a single resource block. For this reason, radioresources can be allocated to more terminal devices within a certainperiod of time. As a result, legacy can be further shortened.

(2) Real-Time Property of Data and Frequency Band

The base station 100 (the transmission processing unit 155) transmits,for example, a signal of data having a lower real-time property in thefirst frequency band and a signal of data having a higher real-timeproperty in the second frequency band.

Referring to FIG. 26 again, the base station 100 transmits a signal ofdata having a lower real-time property in the CC 31 and a signal of datahaving a higher real-time property in the CC 33, as an example. The datahaving a higher real-time property is, for example, audio data or videodata.

Accordingly, latency of data having a higher real-time property, forexample, can be further shortened.

Note that the base station 100 (the processing unit 150) may determine areal-time property of data on the basis of an QCI. The QCI may be a QCIof a bearer corresponding to the data. Description of this point is thesame as that in the above-described modified example. Thus, overlappingdescription is omitted here.

(3) Throughput/Data Size and Frequency Band

The base station 100 (the transmission processing unit 155) may transmita signal of information in a larger size in the first frequency band anda signal a signal of information in a smaller size in the secondfrequency band. As an example, the information in the larger size may bedata in a larger size, and the information in the smaller size may becontrol information or data in a smaller size. Accordingly, radioresources can be used more efficiently.

The base station 100 (the transmission processing unit 155) may transmita signal of data that requires a higher throughput in the firstfrequency band and a signal of data that requires a lower throughput inthe second frequency band. Accordingly, a high throughput can be gainedfor the data that requires a higher throughput.

(4) Others

The base station 100 may alter the length of the time frame of thesecond frequency band. For example, the base station 100 may alter thelength of the time frame of the second frequency band dynamically orsemi-statically. In addition, the base station 100 may also alter alength of a time frame of another frequency band (e.g., the firstfrequency band, or the like).

8. Application Example

The technology of the present disclosure can be applied to variousproducts. The base station 100 may be realized as any type of evolvednode B (eNB), for example, a macro eNB, a small eNB, or the like. Asmall eNB may be an eNB that covers a smaller cell than a macro cell,such as a pico eNB, a micro eNB, or a home (femto) eNB. Alternatively,the base station 100 may be realized as another type of base stationsuch as a node B or a base transceiver station (BTS). The base station100 may include a main body that controls radio communication (alsoreferred to as a base station device) and one or more remote radio heads(RRHs) disposed in a different place from the main body. In addition,various types of terminals to be described below may operate as the basestation 100 by temporarily or semi-permanently executing the basestation function. Furthermore, at least some of constituent elements ofthe base station 100 may be realized in a base station device or amodule for a base station device.

In addition, the terminal device 200 may be realized as, for example, amobile terminal such as a smartphone, a tablet personal computer (PC), anotebook PC, a portable game terminal, a portable/dongle type mobilerouter, or a digital camera, or an in-vehicle terminal such as a carnavigation device. In addition, the terminal device 200 may be realizedas a terminal that performs machine-to-machine (M2M) communication (alsoreferred to as a machine type communication (MTC) terminal).Furthermore, at least some of constituent elements of the terminaldevice 200 may be realized in a module mounted in such a terminal (forexample, an integrated circuit module configured in one die).

<8.1. Application Example with Regard to Base Station>

First Application Example

FIG. 27 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 may be connected to each other via an RF cable.

Each of the antennas 810 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the base station device 820 to transmit and receive radiosignals. The eNB 800 may include the multiple antennas 810, asillustrated in FIG. 27. For example, the multiple antennas 810 may becompatible with multiple frequency bands used by the eNB 800. AlthoughFIG. 27 illustrates the example in which the eNB 800 includes themultiple antennas 810, the eNB 800 may also include a single antenna810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a radio communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of a higher layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in signalsprocessed by the radio communication interface 825, and transfers thegenerated packet via the network interface 823. The controller 821 maybundle data from multiple base band processors to generate the bundledpacket, and transfer the generated bundled packet. The controller 821may have logical functions of performing control such as radio resourcecontrol, radio bearer control, mobility management, admission control,and scheduling. The control may be performed in corporation with an eNBor a core network node in the vicinity. The memory 822 includes RAM andROM, and stores a program that is executed by the controller 821, andvarious types of control data (such as a terminal list, transmissionpower data, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In this case, the eNB 800 may be connected to a corenetwork node or another eNB through a logical interface (e.g. S1interface or X2 interface). The network interface 823 may also be awired communication interface or a radio communication interface forradio backhaul. If the network interface 823 is a radio communicationinterface, the network interface 823 may use a higher frequency band forradio communication than a frequency band used by the radiocommunication interface 825.

The radio communication interface 825 supports any cellularcommunication scheme such as Long Term Evolution (LTE) and LTE-Advanced,and provides radio connection to a terminal positioned in a cell of theeNB 800 via the antenna 810. The radio communication interface 825 maytypically include, for example, a baseband (BB) processor 826 and an RFcircuit 827. The BB processor 826 may perform, for example,encoding/decoding, modulating/demodulating, andmultiplexing/demultiplexing, and performs various types of signalprocessing of layers (such as L1, medium access control (MAC), radiolink control (RLC), and a packet data convergence protocol (PDCP)). TheBB processor 826 may have a part or all of the above-described logicalfunctions instead of the controller 821. The BB processor 826 may be amemory that stores a communication control program, or a module thatincludes a processor and a related circuit configured to execute theprogram. Updating the program may allow the functions of the BBprocessor 826 to be changed. The module may be a card or a blade that isinserted into a slot of the base station device 820. Alternatively, themodule may also be a chip that is mounted on the card or the blade.Meanwhile, the RF circuit 827 may include, for example, a mixer, afilter, and an amplifier, and transmits and receives radio signals viathe antenna 810.

The radio communication interface 825 may include the multiple BBprocessors 826, as illustrated in FIG. 27. For example, the multiple BBprocessors 826 may be compatible with multiple frequency bands used bythe eNB 800. The radio communication interface 825 may include themultiple RF circuits 827, as illustrated in FIG. 27. For example, themultiple RF circuits 827 may be compatible with multiple antennaelements. Although FIG. 27 illustrates the example in which the radiocommunication interface 825 includes the multiple BB processors 826 andthe multiple RF circuits 827, the radio communication interface 825 mayalso include a single BB processor 826 or a single RF circuit 827.

In the eNB 800 shown in FIG. 27, one or more structural elementsincluded in the processing unit 150 (the selection unit 151, thenotification unit 153, the transmission processing unit 155 and/or thereception processing unit 157) described with reference to FIG. 7 may beimplemented by the radio communication interface 825. Alternatively, atleast some of these constituent elements may be implemented by thecontroller 821. As an example, a module which includes a part (forexample, the BB processor 826) or all of the radio communicationinterface 825 and/or the controller 821 may be mounted in eNB 800, andthe one or more structural elements may be implemented by the module. Inthis case, the module may store a program for causing the processor tofunction as the one or more structural elements (i.e., a program forcausing the processor to execute operations of the one or morestructural elements) and may execute the program. As another example,the program for causing the processor to function as the one or morestructural elements may be installed in the eNB 800, and the radiocommunication interface 825 (for example, the BB processor 826) and/orthe controller 821 may execute the program. As described above, the eNB800, the base station device 820, or the module may be provided as adevice which includes the one or more structural elements, and theprogram for causing the processor to function as the one or morestructural elements may be provided. In addition, a readable recordingmedium in which the program is recorded may be provided.

In addition, in the eNB 800 shown in FIG. 27, the radio communicationunit 120 described with reference to FIG. 7 may be implemented by theradio communication interface 825 (for example, the RF circuit 827).Moreover, the antenna unit 110 may be implemented by the antenna 810. Inaddition, the network communication unit 130 may be implemented by thecontroller 821 and/or the network interface 823.

Second Application Example

FIG. 28 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure may be applied. An eNB 830 includes one or more antennas 840,a base station device 850, and an RRH 860. Each antenna 840 and the RRH860 may be connected to each other via an RF cable. The base stationdevice 850 and the RRH 860 may be connected to each other via a highspeed line such as an optical fiber cable.

Each of the antennas 840 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the RRH 860 to transmit and receive radio signals. The eNB 830may include the multiple antennas 840, as illustrated in FIG. 28. Forexample, the multiple antennas 840 may be compatible with multiplefrequency bands used by the eNB 830. Although FIG. 28 illustrates theexample in which the eNB 830 includes the multiple antennas 840, the eNB830 may also include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a radio communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are the same as the controller 821, the memory822, and the network interface 823 described with reference to FIG. 27.

The radio communication interface 855 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and provides radiocommunication to a terminal positioned in a sector corresponding to theRRH 860 via the RRH 860 and the antenna 840. The radio communicationinterface 855 may typically include, for example, a BB processor 856.The BB processor 856 is the same as the BB processor 826 described withreference to FIG. 27, except the BB processor 856 is connected to the RFcircuit 864 of the RRH 860 via the connection interface 857. The radiocommunication interface 855 may include the multiple BB processors 856,as illustrated in FIG. 28. For example, the multiple BB processors 856may be compatible with multiple frequency bands used by the eNB 830.Although FIG. 28 illustrates the example in which the radiocommunication interface 855 includes the multiple BB processors 856, theradio communication interface 855 may also include a single BB processor856.

The connection interface 857 is an interface for connecting the basestation device 850 (radio communication interface 855) to the RRH 860.The connection interface 857 may also be a communication module forcommunication in the above-described high speed line that connects thebase station device 850 (radio communication interface 855) to the RRH860.

The RRH 860 includes a connection interface 861 and a radiocommunication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(radio communication interface 863) to the base station device 850. Theconnection interface 861 may also be a communication module forcommunication in the above-described high speed line.

The radio communication interface 863 transmits and receives radiosignals via the antenna 840. The radio communication interface 863 maytypically include, for example, the RF circuit 864. The RF circuit 864may include, for example, a mixer, a filter, and an amplifier, andtransmits and receives radio signals via the antenna 840. The radiocommunication interface 863 may include multiple RF circuits 864, asillustrated in FIG. 28. For example, the multiple RF circuits 864 maysupport multiple antenna elements. Although FIG. 28 illustrates theexample in which the radio communication interface 863 includes themultiple RF circuits 864, the radio communication interface 863 may alsoinclude a single RF circuit 864.

In the eNB 830 shown in FIG. 28, one or more structural elementsincluded in the processing unit 150 (the selection unit 151, thenotification unit 153, the transmission processing unit 155 and/or thereception processing unit 157) described with reference to FIG. 7 may beimplemented by the radio communication interface 855 and/or the radiocommunication interface 863. Alternatively, at least some of theseconstituent elements may be implemented by the controller 851. As anexample, a module which includes a part (for example, the BB processor856) or all of the radio communication interface 855 and/or thecontroller 851 may be mounted in eNB 830, and the one or more structuralelements may be implemented by the module. In this case, the module maystore a program for causing the processor to function as the one or morestructural elements (i.e., a program for causing the processor toexecute operations of the one or more structural elements) and mayexecute the program. As another example, the program for causing theprocessor to function as the one or more structural elements may beinstalled in the eNB 830, and the radio communication interface 855 (forexample, the BB processor 856) and/or the controller 851 may execute theprogram. As described above, the eNB 830, the base station device 850,or the module may be provided as a device which includes the one or morestructural elements, and the program for causing the processor tofunction as the one or more structural elements may be provided. Inaddition, a readable recording medium in which the program is recordedmay be provided.

In addition, in the eNB 830 shown in FIG. 28, the radio communicationunit 120 described, for example, with reference to FIG. 7 may beimplemented by the radio communication interface 863 (for example, theRF circuit 864). Moreover, the antenna unit 110 may be implemented bythe antenna 840. In addition, the network communication unit 130 may beimplemented by the controller 851 and/or the network interface 853.

<8.2. Application Example with Regard to Terminal Device>

First Application Example

FIG. 29 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure may be applied. The smartphone 900 includes a processor 901,a memory 902, a storage 903, an external connection interface 904, acamera 906, a sensor 907, a microphone 908, an input device 909, adisplay device 910, a speaker 911, a radio communication interface 912,one or more antenna switches 915, one or more antennas 916, a bus 917, abattery 918, and an auxiliary controller 919.

The processor 901 may be, for example, a CPU or a system on a chip(SoC), and controls functions of an application layer and another layerof the smartphone 900. The memory 902 includes RAM and ROM, and stores aprogram that is executed by the processor 901, and data. The storage 903may include a storage medium such as a semiconductor memory and a harddisk. The external connection interface 904 is an interface forconnecting an external device such as a memory card and a universalserial bus (USB) device to the smartphone 900.

The camera 906 includes an image sensor such as a charge coupled device(CCD) and a complementary metal oxide semiconductor (CMOS), andgenerates a captured image. The sensor 907 may include a group ofsensors such as a measurement sensor, a gyro sensor, a geomagneticsensor, and an acceleration sensor. The microphone 908 converts soundsthat are input to the smartphone 900 to audio signals. The input device909 includes, for example, a touch sensor configured to detect touchonto a screen of the display device 910, a keypad, a keyboard, a button,or a switch, and receives an operation or an information input from auser. The display device 910 includes a screen such as a liquid crystaldisplay (LCD) and an organic light-emitting diode (OLED) display, anddisplays an output image of the smartphone 900. The speaker 911 convertsaudio signals that are output from the smartphone 900 to sounds.

The radio communication interface 912 supports any cellularcommunication scheme such as LTE and LTE-Advanced, and performs radiocommunication. The radio communication interface 912 may typicallyinclude, for example, a BB processor 913 and an RF circuit 914. The BBprocessor 913 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. Meanwhile,the RF circuit 914 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna 916.The radio communication interface 912 may also be a one chip module thathas the BB processor 913 and the RF circuit 914 integrated thereon. Theradio communication interface 912 may include the multiple BB processors913 and the multiple RF circuits 914, as illustrated in FIG. 29.Although FIG. 29 illustrates the example in which the radiocommunication interface 912 includes the multiple BB processors 913 andthe multiple RF circuits 914, the radio communication interface 912 mayalso include a single BB processor 913 or a single RF circuit 914.

Furthermore, in addition to a cellular communication scheme, the radiocommunication interface 912 may support another type of radiocommunication scheme such as a short-distance wireless communicationscheme, a near field communication scheme, and a radio local areanetwork (LAN) scheme. In that case, the radio communication interface912 may include the BB processor 913 and the RF circuit 914 for eachradio communication scheme.

Each of the antenna switches 915 switches connection destinations of theantennas 916 among multiple circuits (such as circuits for differentradio communication schemes) included in the radio communicationinterface 912.

Each of the antennas 916 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the radio communication interface 912 to transmit and receiveradio signals. The smartphone 900 may include the multiple antennas 916,as illustrated in FIG. 29. Although FIG. 29 illustrates the example inwhich the smartphone 900 includes the multiple antennas 916, thesmartphone 900 may also include a single antenna 916.

Furthermore, the smartphone 900 may include the antenna 916 for eachradio communication scheme. In that case, the antenna switches 915 maybe omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the radio communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to blocksof the smartphone 900 illustrated in FIG. 29 via feeder lines, which arepartially shown as dashed lines in the figure. The auxiliary controller919 operates a minimum necessary function of the smartphone 900, forexample, in a sleep mode.

In the smartphone 900 shown in FIG. 29, one or more structural elementsincluded in the processing unit 240 described with reference to FIG. 8(the information acquisition unit 241, the notification unit 243, thetransmission processing unit 245 and/or the reception processing unit247) may be implemented by the radio communication interface 912.Alternatively, at least some of these constituent elements may beimplemented by the processor 901 or the auxiliary controller 919. As anexample, a module which includes a part (for example, the BB processor913) or all of the radio communication interface 912, the processor 901and/or the auxiliary controller 919 may be mounted in the smartphone900, and the one or more structural elements may be implemented by themodule. In this case, the module may store a program for causing theprocessor to function as the one or more structural elements (i.e., aprogram for causing the processor to execute operations of the one ormore structural elements) and may execute the program. As anotherexample, the program for causing the processor to function as the one ormore structural elements may be installed in the smartphone 900, and theradio communication interface 912 (for example, the BB processor 913),the processor 901 and/or the auxiliary controller 919 may execute theprogram. As described above, the smartphone 900 or the module may beprovided as a device which includes the one or more structural elements,and the program for causing the processor to function as the one or morestructural elements may be provided. In addition, a readable recordingmedium in which the program is recorded may be provided.

In addition, in the smartphone 900 shown in FIG. 29, the radiocommunication unit 220 described, for example, with reference to FIG. 8may be implemented by the radio communication interface 912 (forexample, the RF circuit 914). Moreover, the antenna unit 210 may beimplemented by the antenna 916.

Second Application Example

FIG. 30 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technology ofthe present disclosure may be applied. The car navigation device 920includes a processor 921, a memory 922, a global positioning system(GPS) module 924, a sensor 925, a data interface 926, a content player927, a storage medium interface 928, an input device 929, a displaydevice 930, a speaker 931, a radio communication interface 933, one ormore antenna switches 936, one or more antennas 937, and a battery 938.

The processor 921 may be, for example, a CPU or a SoC, and controls anavigation function and another function of the car navigation device920. The memory 922 includes RAM and ROM, and stores a program that isexecuted by the processor 921, and data.

The GPS module 924 uses GPS signals received from a GPS satellite tomeasure a position (such as latitude, longitude, and altitude) of thecar navigation device 920. The sensor 925 may include a group of sensorssuch as a gyro sensor, a geomagnetic sensor, and a barometric sensor.The data interface 926 is connected to, for example, an in-vehiclenetwork 941 via a terminal that is not shown, and acquires datagenerated by the vehicle, such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium(such as a CD and a DVD) that is inserted into the storage mediuminterface 928. The input device 929 includes, for example, a touchsensor configured to detect touch onto a screen of the display device930, a button, or a switch, and receives an operation or an informationinput from a user. The display device 930 includes a screen such as aLCD or an OLED display, and displays an image of the navigation functionor content that is reproduced. The speaker 931 outputs sounds of thenavigation function or the content that is reproduced.

The radio communication interface 933 supports any cellularcommunication scheme such as LET and LTE-Advanced, and performs radiocommunication. The radio communication interface 933 may typicallyinclude, for example, a BB processor 934 and an RF circuit 935. The BBprocessor 934 may perform, for example, encoding/decoding,modulating/demodulating, and multiplexing/demultiplexing, and performsvarious types of signal processing for radio communication. Meanwhile,the RF circuit 935 may include, for example, a mixer, a filter, and anamplifier, and transmits and receives radio signals via the antenna 937.The radio communication interface 933 may be a one chip module havingthe BB processor 934 and the RF circuit 935 integrated thereon. Theradio communication interface 933 may include the multiple BB processors934 and the multiple RF circuits 935, as illustrated in FIG. 30.Although FIG. 30 illustrates the example in which the radiocommunication interface 933 includes the multiple BB processors 934 andthe multiple RF circuits 935, the radio communication interface 933 mayalso include a single BB processor 934 or a single RF circuit 935.

Furthermore, in addition to a cellular communication scheme, the radiocommunication interface 933 may support another type of radiocommunication scheme such as a short-distance wireless communicationscheme, a near field communication scheme, and a radio LAN scheme. Inthat case, the radio communication interface 933 may include the BBprocessor 934 and the RF circuit 935 for each radio communicationscheme.

Each of the antenna switches 936 switches connection destinations of theantennas 937 among multiple circuits (such as circuits for differentradio communication schemes) included in the radio communicationinterface 933.

Each of the antennas 937 includes a single or multiple antenna elements(such as multiple antenna elements included in an MIMO antenna), and isused for the radio communication interface 933 to transmit and receiveradio signals. The car navigation device 920 may include the multipleantennas 937, as illustrated in FIG. 30. Although FIG. 30 illustratesthe example in which the car navigation device 920 includes the multipleantennas 937, the car navigation device 920 may also include a singleantenna 937.

Furthermore, the car navigation device 920 may include the antenna 937for each radio communication scheme. In that case, the antenna switches936 may be omitted from the configuration of the car navigation device920.

The battery 938 supplies power to blocks of the car navigation device920 illustrated in FIG. 30 via feeder lines that are partially shown asdashed lines in the figure. The battery 938 accumulates power suppliedform the vehicle.

In the car navigation device 920 shown in FIG. 30, one or morestructural elements included in the processing unit 240 described withreference to FIG. 8 (the information acquisition unit 241, thenotification unit 243, the transmission processing unit 245, and/or thereception processing unit 247) may be implemented by the radiocommunication interface 933. Alternatively, at least some of theseconstituent elements may be implemented by the processor 921. As anexample, a module which includes a part (for example, the BB processor934) or all of the radio communication interface 933 and/or theprocessor 921 may be mounted in the car navigation device 920, and theone or more structural elements may be implemented by the module. Inthis case, the module may store a program for causing the processor tofunction as the one or more structural elements (i.e., a program forcausing the processor to execute operations of the one or morestructural elements) and may execute the program. As another example,the program for causing the processor to function as the one or morestructural elements may be installed in the car navigation device 920,and the radio communication interface 933 (for example, the BB processor934) and/or the processor 921 may execute the program. As describedabove, the car navigation device 920 or the module may be provided as adevice which includes the one or more structural elements, and theprogram for causing the processor to function as the one or morestructural elements may be provided. In addition, a readable recordingmedium in which the program is recorded may be provided.

In addition, in the car navigation device 920 shown in FIG. 30, theradio communication unit 220 described, for example, with reference toFIG. 8 may be implemented by the radio communication interface 933 (forexample, the RF circuit 935). Moreover, the antenna unit 210 may beimplemented by the antenna 937.

The technology of the present disclosure may also be realized as anin-vehicle system (or a vehicle) 940 including one or more blocks of thecar navigation device 920, the in-vehicle network 941, and a vehiclemodule 942. In other words, the in-vehicle system (or a vehicle) 940 maybe provided as a device which includes the one or more structuralelements (the information acquisition unit 241, the notification unit243, the transmission processing unit 245, and/or the receptionprocessing unit 247). The vehicle module 942 generates vehicle data suchas vehicle speed, engine speed, and trouble information, and outputs thegenerated data to the in-vehicle network 941.

9. Conclusion

So far, devices and processes according to embodiments of the presentdisclosure have been described with reference to FIGS. 3 to 30.

According to the embodiment of the present disclosure, the base station100 includes the selection unit 151 which selects a frequency band towhich non-orthogonal multiple access is applied and at least one layeramong a plurality of layers that are to be multiplexed in the frequencyband for the non-orthogonal multiple access as a band and a layer to beused for transmission the terminal device 200, and the notification unit153 which notifies the terminal device 200 of the frequency band and theat least one layer.

In addition, according to the embodiment of the present disclosure, theterminal device 200 includes the information acquisition unit 241 whichacquires band information indicating the frequency band that is afrequency band to which non-orthogonal multiple access is applied and isselected as a band to be used for transmission to the terminal deviceand layer information indicating the at least one layer which is atleast one layer among the plurality of layers that are to be multiplexedin the frequency band for the non-orthogonal multiple access and isselected as a layer to be used for transmission to the terminal device,and the reception processing unit 247 which decodes a signal transmittedon the at least one layer in the frequency band.

Accordingly, a burden of scheduling in non-orthogonal multiple access,for example, can be further reduced.

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

Although non-orthogonal multiple access using power allocation (morespecifically, non-orthogonal multiple access using SPC) has beendescribed as an example of non-orthogonal multiple access, for example,the present disclosure is not limited thereto. For example, IDMA, SCMA,and the like may be applied as non-orthogonal multiple access.

In addition, although the embodiments have been described on the basisof the technology of LTE/LTE-A, for example, the present disclosure isnot limited thereto. Although the example in which channels decided forLTE/LTE-A (e.g., a PDCCH, a PDSCH and/or BMCH) are used has beendescribed as an example, other channels (channels with other names) maybe used.

In addition, processing steps in processes of the present specificationmay not necessarily be executed in, for example, a time series manner inthe order described in the flowcharts or sequence diagrams. Theprocessing steps in the processes may also be executed in, for example,a different order from the order described in the flowcharts or sequencediagrams, or may be executed in parallel.

In addition, a computer program for causing a processor (for example, aCPU, a DSP, or the like) provided in a device of the presentspecification (for example, a base station, a base station device or amodule for a base station device, or a terminal device or a module for aterminal device) to function as a constituent element of the device (forexample, the selection unit, the notification unit, the transmissionprocessing unit, the transmission processing unit, the receptionprocessing unit, the information acquisition unit, and/or the like) (inother words, a computer program for causing the processor to executeoperations of the constituent element of the device) can also becreated. In addition, a recording medium in which the computer programis recorded may also be provided. Further, a device that includes amemory in which the computer program is stored and one or moreprocessors that can execute the computer program (a base station, a basestation device or a module for a base station device, or a terminaldevice or a module for a terminal device) may also be provided. Inaddition, a method including an operation of the constituent element ofthe device (for example, the selection unit, the notification unit, thetransmission processing unit, the transmission processing unit, thereception processing unit, the information acquisition unit, and/or thelike) is also included in the technology of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

An apparatus including:

a selection unit configured to select a frequency band to whichnon-orthogonal multiple access is applied and at least one layer among aplurality of layers that are to be multiplexed in the frequency band forthe non-orthogonal multiple access, as a band and a layer to be used fortransmission to a terminal device; and

a notification unit configured to notify the terminal device of thefrequency band and the at least one layer.

(2)

The apparatus according to (1),

in which the non-orthogonal multiple access is non-orthogonal multipleaccess using power allocation, and

the plurality of layers are a plurality of layers that are to bemultiplexed in the frequency band using power allocation.

(3)

The apparatus according to (2), in which the non-orthogonal multipleaccess is non-orthogonal multiple access using superposition coding(SPC).

(4)

The apparatus according to (2) or (3),

in which the selection unit selects the frequency band and a layer towhich maximum power is allocated among the plurality of layers, as aband and a layer to be used for transmission to another terminal devicethat does not support the non-orthogonal multiple access, and

the notification unit notifies the other terminal device of thefrequency band.

(5)

The apparatus according to any one of (1) to (4), in which the terminaldevice is a terminal device that supports the non-orthogonal multipleaccess.

(6)

The apparatus according to any one of (1) to (5),

in which the frequency band is a component carrier, and

the selection unit selects the frequency band as a secondary componentcarrier to be used for transmission to the terminal device, and selectsthe at least one layer as a layer to be used for transmission to theterminal device in the secondary component carrier.

(7)

The apparatus according to any one of (1) to (5), in which the selectionunit selects the frequency band as a band of a handover destination ofthe terminal device, and selects the at least one layer as a layer to beused for transmission to the terminal device in the band of the handoverdestination.

(8)

The apparatus according to any one of (1) to (7),

in which the selection unit re-selects another layer among the pluralityof layers as a layer to be used for transmission to the terminal device,and

the notification unit notifies the terminal device of the other layer.

(9)

The apparatus according to any one of (1) to (8), in which the at leastone layer is one layer among the plurality of layers.

(10)

The apparatus according to any one of (1) to (19), further including:

a transmission processing unit configured to transmit a signal in thefrequency band,

in which the transmission processing unit transmits a signal of aphysical data channel on each of the plurality of layers in thefrequency band.

(11)

The apparatus according to (10), in which the transmission processingunit transmits a signal of the physical control channel on one layer ofthe plurality of layers or without multiplexing in the frequency band.

(12)

The apparatus according to (11), in which the signal of the physicalcontrol channel includes a signal of scheduling information with respectto each of the plurality of layers.

(13)

The apparatus according to (10), in which the transmission processingunit transmits a signal of a physical control channel on each of theplurality of layers in the frequency band.

(14)

The apparatus according to any one of (1) to (13), in which theplurality of layers include a first layer of which a length of a timeframe is a first length and a second layer of which a length of a timeframe is a second length that is shorter than the first length.

(15)

The apparatus according to (14), in which the first length is equal to alength of a time frame of another frequency band to which thenon-orthogonal multiple access is not applied.

(16)

The apparatus according to (14) or (15), further including:

a transmission processing unit configured to transmit a signal in thefrequency band,

in which the transmission processing unit transmits a signal of datahaving a lower real-time property on the first layer and a signal ofdata having a higher real-time property on the second layer in thefrequency band.

(17)

The apparatus according to (14) or (15), in which the time frame is asubframe.

(18)

A method that is performed by a processor, the method including:

selecting a frequency band to which non-orthogonal multiple access isapplied and at least one layer among a plurality of layers that are tobe multiplexed in the frequency band for the non-orthogonal multipleaccess, as a band and a layer to be used for transmission to a terminaldevice; and

notifying the terminal device of the frequency band and the at least onelayer.

(19)

An apparatus including:

an acquisition unit configured to acquire band information indicating afrequency band that is a frequency band to which non-orthogonal multipleaccess is applied and selected as a band to be used for transmission toa terminal device, and layer information indicating at least one layerwhich is at least one layer among a plurality of layers that are to bemultiplexed in the frequency band for the non-orthogonal multiple accessand selected as a layer to be used for transmission to the terminaldevice; and

a reception processing unit configured to decode a signal to betransmitted on the at least one layer in the frequency band.

(20)

The apparatus according to (19), further including:

a notification unit configured to notify a base station of capabilityinformation indicating that the terminal device supports thenon-orthogonal multiple access.

(21)

The apparatus according to any one of (1) to (17), in which theapparatus is a base station, a base station apparatus for the basestation, or a module for the base station apparatus.

(22)

The apparatus according to (19) or (20), in which the apparatus is theterminal device or a module for the terminal device.

(23)

A program causing a processor to execute:

selecting a frequency band to which non-orthogonal multiple access isapplied and at least one layer among a plurality of layers that are tobe multiplexed in the frequency band for the non-orthogonal multipleaccess, as a band and a layer to be used for transmission to a terminaldevice; and

notifying the terminal device of the frequency band and the at least onelayer.

(24)

A readable storage medium having a program stored therein, the programcausing a processor to execute:

selecting a frequency band to which non-orthogonal multiple access isapplied and at least one layer among a plurality of layers that are tobe multiplexed in the frequency band for the non-orthogonal multipleaccess, as a band and a layer to be used for transmission to a terminaldevice; and

notifying the terminal device of the frequency band and the at least onelayer.

(25)

A method including:

acquiring band information indicating a frequency band that is afrequency band to which non-orthogonal multiple access is applied andselected as a band to be used for transmission to a terminal device, andlayer information indicating at least one layer which is at least onelayer among a plurality of layers that are to be multiplexed in thefrequency band for the non-orthogonal multiple access and selected as alayer to be used for transmission to the terminal device; and

decoding a signal to be transmitted on the at least one layer in thefrequency band.

(26)

A program causing a processor to execute:

acquiring band information indicating a frequency band that is afrequency band to which non-orthogonal multiple access is applied andselected as a band to be used for transmission to a terminal device, andlayer information indicating at least one layer which is at least onelayer among a plurality of layers that are to be multiplexed in thefrequency band for the non-orthogonal multiple access and selected as alayer to be used for transmission to the terminal device; and

decoding a signal to be transmitted on the at least one layer in thefrequency band.

(27)

A readable storage medium having a program stored therein, the programcausing a processor to execute:

acquiring band information indicating a frequency band that is afrequency band to which non-orthogonal multiple access is applied andselected as a band to be used for transmission to a terminal device, andlayer information indicating at least one layer which is at least onelayer among a plurality of layers that are to be multiplexed in thefrequency band for the non-orthogonal multiple access and selected as alayer to be used for transmission to the terminal device; and

decoding a signal to be transmitted on the at least one layer in thefrequency band.

REFERENCE SIGNS LIST

-   1 system-   100 base station-   151 selection unit-   153 notification unit-   155 transmission processing unit-   157 reception processing unit-   200 terminal device-   241 information acquisition unit-   243 notification unit-   245 transmission processing unit-   247 reception processing unit

The invention claimed is:
 1. An apparatus comprising: a selection unitconfigured to select a frequency band to which non-orthogonal multipleaccess is applied and at least one layer among a plurality of layersthat are to be multiplexed in the frequency band for the non-orthogonalmultiple access, as a band and a layer to be used for transmission to aterminal device; and a notification unit configured to notify theterminal device of the frequency band and the at least one layer.
 2. Theapparatus according to claim 1, wherein the non-orthogonal multipleaccess is non-orthogonal multiple access using power allocation, and theplurality of layers are a plurality of layers that are to be multiplexedin the frequency band using power allocation.
 3. The apparatus accordingto claim 2, wherein the non-orthogonal multiple access is non-orthogonalmultiple access using superposition coding (SPC).
 4. The apparatusaccording to claim 2, wherein the selection unit selects the frequencyband and a layer to which maximum power is allocated among the pluralityof layers, as a band and a layer to be used for transmission to anotherterminal device that does not support the non-orthogonal multipleaccess, and the notification unit notifies the other terminal device ofthe frequency band.
 5. The apparatus according to claim 1, wherein theterminal device is a terminal device that supports the non-orthogonalmultiple access.
 6. The apparatus according to claim 1, wherein thefrequency band is a component carrier, and the selection unit selectsthe frequency band as a secondary component carrier to be used fortransmission to the terminal device, and selects the at least one layeras a layer to be used for transmission to the terminal device in thesecondary component carrier.
 7. The apparatus according to claim 1,wherein the selection unit selects the frequency band as a band of ahandover destination of the terminal device, and selects the at leastone layer as a layer to be used for transmission to the terminal devicein the band of the handover destination.
 8. The apparatus according toclaim 1, wherein the selection unit re-selects another layer among theplurality of layers as a layer to be used for transmission to theterminal device, and the notification unit notifies the terminal deviceof the other layer.
 9. The apparatus according to claim 1, wherein theat least one layer is one layer among the plurality of layers.
 10. Theapparatus according to claim 1, further comprising: a transmissionprocessing unit configured to transmit a signal in the frequency band,wherein the transmission processing unit transmits a signal of aphysical data channel on each of the plurality of layers in thefrequency band.
 11. The apparatus according to claim 10, wherein thetransmission processing unit transmits a signal of the physical controlchannel on one layer of the plurality of layers or without multiplexingin the frequency band.
 12. The apparatus according to claim 11, whereinthe signal of the physical control channel includes a signal ofscheduling information with respect to each of the plurality of layers.13. The apparatus according to claim 10, wherein the transmissionprocessing unit transmits a signal of a physical control channel on eachof the plurality of layers in the frequency band.
 14. The apparatusaccording to claim 1, wherein the plurality of layers include a firstlayer of which a length of a time frame is a first length and a secondlayer of which a length of a time frame is a second length that isshorter than the first length.
 15. The apparatus according to claim 14,wherein the first length is equal to a length of a time frame of anotherfrequency band to which the non-orthogonal multiple access is notapplied.
 16. The apparatus according to claim 14, further comprising: atransmission processing unit configured to transmit a signal in thefrequency band, wherein the transmission processing unit transmits asignal of data having a lower real-time property on the first layer anda signal of data having a higher real-time property on the second layerin the frequency band.
 17. The apparatus according to claim 14, whereinthe time frame is a subframe.
 18. A method that is performed by aprocessor, the method comprising: selecting a frequency band to whichnon-orthogonal multiple access is applied and at least one layer among aplurality of layers that are to be multiplexed in the frequency band forthe non-orthogonal multiple access, as a band and a layer to be used fortransmission to a terminal device; and notifying the terminal device ofthe frequency band and the at least one layer.
 19. An apparatuscomprising: an acquisition unit configured to acquire band informationindicating a frequency band that is a frequency band to whichnon-orthogonal multiple access is applied and selected as a band to beused for transmission to a terminal device, and layer informationindicating at least one layer which is at least one layer among aplurality of layers that are to be multiplexed in the frequency band forthe non-orthogonal multiple access and selected as a layer to be usedfor transmission to the terminal device; and a reception processing unitconfigured to decode a signal to be transmitted on the at least onelayer in the frequency band.
 20. The apparatus according to claim 19,further comprising: a notification unit configured to notify a basestation of capability information indicating that the terminal devicesupports the non-orthogonal multiple access.